Answer:
A. The causal connection is valid. Students who spend more time and effort studying will be able to memorize more information, so their test grades will be higher.
Step-by-step Explanation:
The causal connection between the test grades of students and the amount of time and effort spent the students spend in studying and preparing for the test appears to be valid. This is valid because students who spend more time and effort studying would most likely be able to memorize more information of which they are most likely to come by in the test they take. Invariably, they'd be able to easily recall what they've memorize and give the right answers to the questions they are asked in the test, and this definitely will earn them higher test grades.
Please help! Been stuck on this for hours Solve the inequality. Express your answer in interval form. (If there is no solution, enter NO SOLUTION.) 2 ≤ |x^2 − 4| < 4
Answer:
(-√8, -√6] ∪ [-√2, 0) ∪ (0, √2] ∪ [√6, √8)
Step-by-step explanation:
The inequality resolves into 4 inequalities. There are 4 intervals in the solution.
Starting at the left, for the absolute value argument less than 0:
2 ≤ -(x^2 -4) . . . . . . . for x^2 -4 ≤ 0
2 ≤ -x^2 +4
-2 ≤ -x^2
2 ≥ x^2 . . . . . . . . . . consistent with the above 4 ≥ x^2
-√2 ≤ x ≤ √2 . . . . . square root; may be limited by other constraints
For the absolute value argument greater than 0:
2 ≤ x^2 -4 . . . . . . . for x^2 -4 ≥ 0
6 ≤ x^2 . . . . . . . . . .consistent with x^2 ≥ 4
-√6 ≥ x ∪ x ≤ √6 . . . . take the square root
__
The inequality on the right can be written as the compound inequality ...
-4 < x^2 -4 < 4
0 < x^2 < 8 . . . . . add 4
0 < |x| < √8 . . . . take the square root
This resolves to ...
-√8 < x < 0 ∪ 0 < x < √8
__
So, the solution set is the set of values of x that satisfy these restrictions on x:
-√2 ≤ x ≤ √2
x ≤ -√6 ∪ x ≤ √6
-√8 < x < 0 ∪ 0 < x < √8
That is a collection of 4 intervals:
(-√8, -√6] ∪ [-√2, 0) ∪ (0, √2] ∪ [√6, √8)
_____
You may be expected to write √8 as 2√2.
__
These intervals are the portions of the red curve that lie between the two horizontal lines. The points on the upper (dashed) line are not part of the solution set. The points on the lower (solid) line are part of the solution set.
Which system of linear inequalities is represented by the
graph?
O y2x - 2 and y = x + 1
O y< x-2 and y> x + 1
O y < x-2 and y? x + 1
O y> x-2 and y < x + 1
Answer:
answer c.
y <= x - 2 and y >= x + 1
Step-by-step explanation:
You wrote the given answers wrong. Here are the right choices that are given as possible solutions:
O y >= x - 2 and y <= x + 1
O y < x - 2 and y > x + 1
O y <= x - 2 and y >= x + 1
O y > x - 2 and y < x + 1
The graph clearly shows two lines and the intended area is shaded and it is clearly including the lines.
Because the lines are included in the solution, by that alone, you can exclude two answers b and d.
Now you still need to decide between the in equalities in answer a and c. Both lines have a gradient of 1, so that does not help to distinguish...
The y intercept of the top line is at y= +1 and the shaded area is bigger then that....
So y >= x + 1 is the right inequality.By now it is absolutely clear that answer c must be the right answer and you are done!
EXTRA
Although you have deduced beyond any doubt, that answer c must be the right answer, you still can check your findings 'to be sure' by looking and checking for the bottom line...
BE CAREFUL, ONLY DO THIS IF YOU HAVE ENOUGH TIME. Again, you already know the right answer, and this is "just to confirm", so what is the harm in that?
By double checking yourself, it will sort of "undermine" your appproach. Basically you are doing something which is strictly spoken not nessasary any more. So I urge you to basically step over the urge to check yourself, and stick to your answer.
However, if you can not resit the temptation of checking to see if you actually found the right answer, you could test the y intercept of the bottom line, which is at y= -2 and the shaded area is smalller then that....
So y <= x - 2 is the right inequality.So again, it is now confirmed that answer c is indeed the right answer.
The correct system of linear inequalities is represented by the graph are,
⇒ y > x - 2
⇒ y < x + 1
What is mean by Inequality?A relation by which we can compare two or more mathematical expression is called an inequality.
Given that;
The system of linear inequalities is shown in graph.
Hence, By graph;
The value of y - intercepts are,
⇒ - 2 and - 1
Hence, The correct system of linear inequalities is represented by the graph are,
⇒ y > x - 2
⇒ y < x + 1
Thus, The correct system of linear inequalities is represented by the graph are,
⇒ y > x - 2
⇒ y < x + 1
Learn more about the inequality visit:
https://brainly.com/question/25944814
#SPJ7
Which of the following is a subset of every set? * 1)Universal Set 2)Null Set 3)Both of these 4)None of these
Answer:
[tex]1[/tex]
Step-by-step explanation:
Universal set contains all elements and of which all other sets are subsets.
One day Pat Unger worked for a total of 8
hours. She worked 3 hours more in the after-
noon than she worked in the morning. How
long did she work in the afternoon?
Answer:
5.5 hours
Step-by-step explanation:
Let the no. of hours worked in morning by Pat = x hours
given that "She worked 3 hours more in the after-
noon than she worked in the morning"
No. of hours worked in Afternoon by Pat = x + 3 hours
Total hours worked in the day = x + x+3 = 2x +3 hours (1)
It is given that Pat worked for 8 hours that day (2)
thus, using 1 and 2 we have
2x +3 = 8
=>2x = 8 - 3 = 5
=> x = 5/2 = 2.5
no. of hours worked in morning by Pat = x hours = 2.5 hours
No. of hours worked in Afternoon by Pat = x + 3 hours = 2.5 + 3 hours
No. of hours worked in Afternoon by Pat = 5.5 hours --- Answer.
what is the solution set for the equation (x+3)(x-8)=0
Answer:
x = -3 x=8
Step-by-step explanation:
(x+3)(x-8)=0
Using the zero product property
x+3 =0 x -8 = 0
x = -3 x=8
PLEEEASE HELLLLP!!!!!!! If x+7=2y and y=2x−1, what is the value of y?
Answer:
13
Step-by-step explanation:
We can add 1 to both sides of the second equation and divide by 2 to get
x = (y-1)/2
We can then substitute x in the first equation to get
(y-1)/2 + 7 = 2y
Multiply by 2
y-1 + 14 = 2y
Subtract y and combine like terms
y = 13
Lola bought x pencils that cost $0.25 each and y erasers that cost $0.50. She spent less than $3. Which graph represents Lola’s purchase?
Answer:
Graph C is the answer.
Step-by-step explanation:
Lola bought X pencils that cost $0.25 and Y erasers that cost $0.50.
Total expenditure is less than $3.
If we represent expense in the equation form then it will be
Expense on pencils + expense on erasers = Total expense which is < 3
0.25X + 0.50Y < 3
Now we divide the inequality by 0.25
X + 2Y < 12
This inequality when graphed, line will be plotted in dots and area below the line will be in the shaded form.
Slope of this line is = (-1/2) {from the standard equation of line y = mx + c)
Now we come to the graphs. Here dotted line graphs are A or C.
We will calculate the slopes of the lines from the graphs A and C to get tha answer.
For Graph A
The end points are (12, 0) and (0, 3)
So slope = (y-y')/(x-x') = (3-0)/(0-12) = -3/12 = -1/4
For Graph C.
End points the line are (0, 6) and (12, 0)
Slope of the line = (0-6)/(12-0) = -6/12 = -1/2
Therefore Graph C is the answer.
Answer:
Graph C is the answer.
Step-by-step explanation:
Lola bought X pencils that cost $0.25 and Y erasers that cost $0.50.
Total expenditure is less than $3.
If we represent expense in the equation form then it will be
Expense on pencils + expense on erasers = Total expense which is < 3
0.25X + 0.50Y < 3
Now we divide the inequality by 0.25
X + 2Y < 12
This inequality when graphed, line will be plotted in dots and area below the line will be in the shaded form.
Slope of this line is = (-1/2) {from the standard equation of line y = mx + c)
Now we come to the graphs. Here dotted line graphs are A or C.
We will calculate the slopes of the lines from the graphs A and C to get tha answer.
For Graph A
The end points are (12, 0) and (0, 3)
So slope = (y-y')/(x-x') = (3-0)/(0-12) = -3/12 = -1/4
For Graph C.
End points the line are (0, 6) and (12, 0)
Slope of the line = (0-6)/(12-0) = -6/12 = -1/2
Therefore Graph C is the answer.
Step-by-step explanation:
make brainiest please
3
Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.
The product of (3 + 2) and a complex number is (17 + 71).
The complex number is
Answer:
5-i
Step-by-step explanation:
Product=multiplication
Let the complex number=x
(3+2i)*x=17+7i
x=17+7i / 3+2i
x=(17-7i)*(3-2i)/(3+2i)*(3+2i)
=51-34i+21i+14i^2 / 9+6i+6i+4i^2
=51+13i+14i^2 / 9+12i+4i^2
= (51+14 - 13i) / 13
= (65 -13i) / 13
= 65 / 13 - 13 i / 13
= 5 - i.
I need help with this one
Answer:
I think 4^0 is the answer
What is the difference written in scientific notation?
Answer:
6.2 × 10⁵
Step-by-step explanation:
Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10.
If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
Which explains why the graph is not a function?
Answer:
56
Step-by-step explanation:
what is an example of a literal question
Answer:
an example of a literal question is "what size do you wear", "what time does the show start", "who was the protagonist in your story" etc
Step-by-step explanation:
Your company made $120,000 in revenue and $50,000 in costs for 2017. What was your profit?
Answer:
$70,000
Step-by-step explanation:
Profit = Revenue - Costs
x = 120,000 - 50,000
x = 70,000
What’s the correct answer for this question?
Answer:
A and B
Step-by-step explanation:
1) Distance to the focus
From (x,y) to the focus(2,-4) {using distance formula}
=√(x-2)²+(y+4)²
2) Distance to the directrix
Is, y+p where P here is (-6)
So
d2 = y+p
= y+(-6)
= y-6
Please help. I’ll mark you as brainliest if correct!
Answer:
product = 40
Step-by-step explanation:
The conjugate of (-2 + 6i) is (-2 - 6i)
You just need to change the sign
(-2 + 6i) (-2 - 6i)
Expand:
4 + 12i + -12i - [tex]36i^{2}[/tex]
4 + 12i + -12i + 36
product = 40
A large car insurance company selected samples of single and married male policyholders and recorded the number who made an insurance claim over the preceding three-year period. Single Policyholders Married Policyholders n1 = 450 n2 = 925 # making claim = 67 # making claim = 93 Using alpha = 0.05, determine whether the claim rates are higher for single male policyholders verses married male policyholders. Solve using the p-value approach only.
Answer:
The null hypothesis is rejected.
There is enough evidence to support the claim that rates are higher for single male policyholders verses married male policyholders (P-value = 0.004).
Step-by-step explanation:
This is a hypothesis test for the difference between proportions.
The claim is that rates are higher for single male policyholders verses married male policyholders.
Then, the null and alternative hypothesis are:
[tex]H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2> 0[/tex]
The significance level is 0.05.
The sample 1 (single group), of size n1=450 has a proportion of p1=0.1489.
[tex]p_1=X_1/n_1=67/450=0.1489[/tex]
The sample 2 (married group), of size n2=925 has a proportion of p2=0.1005.
[tex]p_2=X_2/n_2=93/925=0.1005[/tex]
The difference between proportions is (p1-p2)=0.0483.
[tex]p_d=p_1-p_2=0.1489-0.1005=0.0483[/tex]
The pooled proportion, needed to calculate the standard error, is:
[tex]p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{67.005+93}{450+925}=\dfrac{160}{1375}=0.1164[/tex]
The estimated standard error of the difference between means is computed using the formula:
[tex]s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.1164*0.8836}{450}+\dfrac{0.1164*0.8836}{925}}\\\\\\s_{p1-p2}=\sqrt{0.0002+0.0001}=\sqrt{0.0003}=0.0184[/tex]
Then, we can calculate the z-statistic as:
[tex]z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{0.0483-0}{0.0184}=\dfrac{0.0483}{0.0184}=2.62[/tex]
This test is a right-tailed test, so the P-value for this test is calculated as (using a z-table):
[tex]P-value=P(z>2.62)=0.004[/tex]
As the P-value (0.004) is smaller than the significance level (0.05), the effect is significant.
The null hypothesis is rejected.
There is enough evidence to support the claim that rates are higher for single male policyholders verses married male policyholders.
A: What are the solutions to the quadratic equation x2+9=0? B: What is the factored form of the quadratic expression x2+9? Select one answer for question A, and select one answer for question B. B: (x+3)(x−3) B: (x+3i)(x−3i) B: (x−3i)(x−3i) B: (x+3)(x+3) A: x=3 or x=−3 A: x=3i or x=−3i A: x=3 A: x=−3i
Answer:
A. The solutions are [tex]x=3i,\:x=-3i[/tex].
B. The factored form of the quadratic expression [tex]x^2+9=(x-3i)(x+3i)[/tex]
Step-by-step explanation:
A. To find the solutions to the quadratic equation [tex]x^2+9=0[/tex] you must:
[tex]\mathrm{Subtract\:}9\mathrm{\:from\:both\:sides}\\\\x^2+9-9=0-9\\\\\mathrm{Simplify}\\\\x^2=-9\\\\\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}\\\\x=\sqrt{-9},\:x=-\sqrt{-9}[/tex]
[tex]x=\sqrt{-9} = \sqrt{-1}\sqrt{9}=\sqrt{9}i=3i\\\\x=-\sqrt{-9}=-\sqrt{-1}\sqrt{9}=-\sqrt{9}i=-3i[/tex]
The solutions are:
[tex]x=3i,\:x=-3i[/tex]
B. Two expressions are equivalent to each other if they represent the same value no matter which values we choose for the variables.
To factor [tex]x^2+9[/tex]:
First, multiply the constant in the polynomial by [tex]i^2[/tex] where [tex]i^2[/tex] is equal to -1.
[tex]x^2+9i^2[/tex]
Since both terms are perfect squares, factor using the difference of squares formula
[tex]a^2-i^2=(a+i)(a-i)[/tex]
[tex]x^2+9=x^2+9i^2=\left(-3i+x\right)\left(3i+x\right)[/tex]
John conducted a taste test on a new brand of French fries. He gave each participant 5 of the new brand of fries and 5 of the old brand of fries and asked them to rate which brand they preferred. The participants rated both brands of fries as equally preferable. Based on this, he recommended to the manufacturer to move ahead with producing this new brand. However, the brand did not sell well. People reported feeling nauseous after they had consumed a whole portion.
Which validity is weak in this example?
a. internal validity
b. external validity
c. statistical validity
d. construct validity
Answer:
b. external validity
Step-by-step explanation:
External Validity is the applicability of the results of an experiment to the real world. Most times, there are threats to the validity of an experiment which could result in little or no effect on the general population. For example, if the method of selection reflects a measure of bias, then this could affect the result. Also if the participants are taking different aspects of the same test, it could also affect its validity as they may not be able to make a correct conclusion. If the sample size is not reflective of the entire population, it could also pose a threat to the validity of the experiment.
John's experiment is weak in its external validity because it cannot be generalized to the entire population of customers. He has to identify the threats to the validity of his experiment and correct them. For example, the sample selection may be biased.
nu
a. Write the equation of a line through the points (-4,- 10) and (8,5) in slope-intercept form.
b. Write the equation in standard form Ax+By = C, where A, B, and C are integers and A>0.
ents
Thoquution
Answer:
5x - 4y = 20
Step-by-step explanation:
First find slope
(5- -10)/(8- -4) = 15/12 = 5/4
(y - 5) = 5/4 (x - 8), multiply everything by 4 so you don't have fractions
4y - 20 = 5x - 40
5x - 4y = 20
Please answer this correctly
Answer:
2 cups more was given to the flower with the most water because 5 cups - 3 cups = 2 cups.
Answer:
2 cups
Step-by-step explanation:
The most water was 5 cups and the least was 3 cups. So:
5-3=2 cups more
Please answer this correctly
Answer:
d = 4
Step-by-step explanation:
Using the formula
A=pq/2
Dont for get to click THANKS
Given fix) = 3x- 1 and g(x) = 2x-3, for which value of x does g(x) = f(2)?
X=
2
О
X= 2
NDI
X=
x=4
Answer:
The value of X would be 4.
Answer:
x=4
Step-by-step explanation:
f(2)=3*2-1=5
g(x)=2x-3=5
2x=8
x=4
g Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Accordingly, his staff recorded the waiting times for 64 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the standard deviation was 4 minutes. The 88% confidence interval for the population mean of waiting times is __________.
Answer:
The 88% confidence interval for the population mean of waiting times is between 7.34 minutes and 22.66 minutes.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 64 - 1 = 63
88% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 63 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.88}{2} = 0.94[/tex]. So we have T = 1.9153
The margin of error is:
M = T*s = 1.9153*4 = 7.66.
In which s is the standard deviation of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 15 - 7.66 = 7.34 minutes
The upper end of the interval is the sample mean added to M. So it is 15 + 7.66 = 22.66 minutes.
The 88% confidence interval for the population mean of waiting times is between 7.34 minutes and 22.66 minutes.
Consider the following numbers Which of these numbers are counting numbers?
{9 ,1, 4/5, √16 , 0.7 , -1, -√2 , π , 0}
The counting number(s) is/are _______(Use a comma to separate answers as needed Do not simplify.)
Answer:
9, 1
Step-by-step explanation:
Counting numbers are numbers that can be used for counting purposes. This group of numbers does not include negative numbers, fractions, zero, decimal numbers etc. They are positively directed whole numbers.
From the question, given the condition not to simplify, then the counting numbers are:
9, 1
others numbers can not be referred to as counting numbers.
What is an equation of the line that is parallel to y = 9 – 5x and passes through (0, 8)?
Answer:
y = 8 - 5x
Step-by-step explanation:
both equations shares the same gradient as they are parallel
from y= 9-5x, the gradient is -5
subst x = 0, y=8, and m= -5 into the y = mx + c to find the value of c
8 = (-5)(0) + c
c= 8
therefore the eqn is y = 8 - 5x
Tara is graphing the equation 4x + 2y = 10. Which of these shows the correct equation in slope-intercept form, slope, and y-intercept?
Answer:
y = -2x + 5
slope = -2
y intercept = 5
Step-by-step explanation:
Slope intercept form of equation of line is given by y = mx + c
where m is the slope of line
c is the y intercept i.e point where given line intersect y axis.
________________________________________________
given equation 4x + 2y = 10
we have to re-write this equation in form y = mx + c
4x + 2y = 10
subtraction 4x from LHS and RHS
4x + 2y - 4x= 10 - 4x
2y = 10- 4x
we have to eliminate 2 from y for that we
divide LHS and RHS by 2 we
2y /2 = 10/2- 4x/2
y = 5 - 2x
rearranging it in y = mx+c form
y = -2x + 5
thus, m = -2 , c = 5
BP Under 30 30-49 Over 50 Total Low 27 38 31 96 Normal 48 90 92 230 High 23 59 72 154 Total 98 187 195 480 What is the percentage of employees who are 30 and over and have normal or low blood pressure? Group of answer choices 67.9% 52.3% 41.7% 75.4%
Answer:
The correct answer to the following question will be Option A (67.9%).
Step-by-step explanation:
As we know,
The number of total employees will be:
= 480
The number of employees having normal or low BP will be:
= 96 + 230
= 326
Hence, the percentage of low or normal BP workers will be:
= [tex](\frac{326}{480} )\times 100 \ percent[/tex]
= [tex]67.9 \ percent[/tex]
Note:- % (percent)
Suppose the demand for a certain brand of a product is given by D(p)equals=StartFraction negative p squared Over 116 EndFraction−p2116plus+200200, where p is the price in dollars. If the price, in terms of the cost c, is expressed as p (c )equals 2 c minus 10p(c)=2c−10, find the demand function in terms of the cost.
Answer:
The demand function in terms of cost is [tex]D(c) = [\frac{[40c- 100 -4c^2 \ ])}{116} ] + 200[/tex]
Step-by-step explanation:
From the question we are told that
The demand for a certain brand of a product is
[tex]D(p) = \frac{-p^2}{116} + 200 ----(1)[/tex]
The price, in terms of the cost c, is expressed as
[tex]p(c) = 2c -6 -----(2)[/tex]
Now substituting equation 2 into equation 1
So
[tex]D(c) = - [\frac{(2c -10 )^2)}{116} ] + 200[/tex]
[tex]D(c) = - [\frac{[4c^2 + 100 -40c \ ])}{116} ] + 200[/tex]
[tex]D(c) = [\frac{[40c- 100 -4c^2 \ ])}{116} ] + 200[/tex]
Factorise fully for this
Answer:
i hope this will help you
Step-by-step explanation:
-9t²v+3tv²
=-3tv(3t-v)
Answer:
[tex]- 3tv(3t - v) \\ [/tex]
Step-by-step explanation:
[tex] - 9 {t}^{2} v + 3t {v}^{2} \\ = - 3tv(3t - v)[/tex]
hope this helps you
brainliest appreciated
good luck! have a nice day!
Jodie Meeks's Free Throws During the 2015-16 NBA season, Jodie Meeks of the Detroit Pistons had a free throw shooting percentage of 0.906 . Assume that the probability Jodie Meeks makes any given free throw is fixed at 0.906 , and that free throws are independent.If Jodie Meeks shoots 6 free throws in a game, what is the probability that he makes at least 5 of them?
Answer:
0.8973
Step-by-step explanation:
Relevant data provided in the question as per the question below:
Free throw shooting percentage = 0.906
Free throws = 6
At least = 5
Based on the above information, the probability is
Let us assume the X signifies the number of free throws
So, Then X ≈ Bin (n = 6, p = 0.906)
[tex]P = (X = x) = $\sum\limits_{x}^6 (0.906)^x (1 - 0.906)^{6-x}, x = 0,1,2,3,.., 6[/tex]
Now
The Required probability = P(X ≥ 5) = P(X = 5) + P(X = 6)
[tex]= $\sum\limits_{5}^6 (0.906)^5 (1 - 0.906)^{6-5} + $\sum\limits_{6}^6 (0.906)^6 (1 - 0.906)^{6-6}[/tex]
= 0.8973
