Answer:
Step-by-step explanation:
a) image attached
b) Lets do the analysis in R , the complete R snippet is as follows
x<- c(89,177,189,354,362,442,965)
y<- c(.4,.6,.48,.66,.61,.69,.99)
# scatterplot
plot(x,y, col="red",pch=16)
# model
fit <- lm(y~x)
summary(fit)
#equation is
#y = 0.4041 + 0.0006211*X
# beta coeffiecients are
fit$coefficients
coef(summary(fit))[, "Std. Error"]
# confidence interval of slope
confint(fit, 'x', level=0.95)
The results are
> summary(fit)
Call:
lm(formula = y ~ x)
Residuals:
1 2 3 4 5 6 7
-0.05940 0.08595 -0.04151 0.03602 -0.01895 0.01136 -0.01346
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 4.041e-01 3.459e-02 11.684 8.07e-05 ***
x 6.211e-04 7.579e-05 8.195 0.00044 ***
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 0.05405 on 5 degrees of freedom
Multiple R-squared: 0.9307, Adjusted R-squared: 0.9168 # model is able to capture 93% of the variation of the data
F-statistic: 67.15 on 1 and 5 DF, p-value: 0.0004403 , p value is less than 0.05 , hence model as a whole is significant
> fit$coefficients
(Intercept) x
0.4041237853 0.0006210758
> coef(summary(fit))[, "Std. Error"]
(Intercept) x
3.458905e-02 7.579156e-05
> confint(fit, 'x', level=0.95)
2.5 % 97.5 %
x 0.0004262474 0.0008159042
c)
> x=c(89,177,189,354,362,442,965)
> y=c(0.40,0.60,0.48,0.66,0.61,0.69,0.99)
>
> ### linear model
> model=lm(y~x)
> summary(model)
Call:
lm(formula = y ~ x)
Residuals:
1 2 3 4 5 6 7
-0.05940 0.08595 -0.04151 0.03602 -0.01895 0.01136 -0.01346
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 4.041e-01 3.459e-02 11.684 8.07e-05 ***
x 6.211e-04 7.579e-05 8.195 0.00044 ***
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 0.05405 on 5 degrees of freedom
Multiple R-squared: 0.9307, Adjusted R-squared: 0.9168
F-statistic: 67.15 on 1 and 5 DF, p-value: 0.0004403
s_e is the Residual standard error from the model and its estimated value is 0.05405. s_e is the standard deviation of the model.
d) 95% confidence interval
> confint(model, confidence=0.95)
2.5 % 97.5 %
(Intercept) 0.3152097913 0.4930377793
x 0.0004262474 0.0008159042
Comment: The estimated confidence interval of slope of x does not include zero. Hence, x has the significant effect on y at 0.05 level of significance.
e)
> predict(model, newdata=data.frame(x=250), interval="confidence", level=0.95)
fit lwr upr
1 0.5593927 0.5020485 0.616737
f)
> predict.lm(model, newdata=data.frame(x=250), interval="prediction", level=0.95)
fit lwr upr
1 0.5593927 0.4090954 0.7096901
What is the final step in solving the inequality –2(5 – 4x) < 6x – 4?
Answer:
–2(5 – 4x) < 6x – 4
<=>
-10 + 8x < 6x - 4
<=>
2x < 6
<=>
x < 3
Hope this helps!
:)
Answer:
Step 1: –10 + 8x < 6x – 4
Step 2: –10 < –2x – 4
Step 3: –6 < –2x
Step 4: ________
What is the final step in solving the inequality –2(5 – 4x) < 6x – 4?
A. x < –3
B. x > –3
C. x < 3
D. x > 3
Step-by-step explanation:
The correct answer here is C. x < 3
Select and place the symbol that will make the statement true |-a| |a|
Answer:
|-a|=|a|
Step-by-step explanation:
The lines beside the a's mean that you are trying to find the absolute value of what's inside. The absolute value of something is the distance it is from 0. You can't have a negative distance so anything inside of absolute value line are positive.
Therefor this is how we can solve this.
|-a| __ |a|
a __ a
a=a
An economist wants to estimate the mean per capita income (in thousands of dollars) for a major city in Texas. Suppose that the mean income is found to be $18.5 for a random sample of 2253 people. Assume the population standard deviation is known to be $6.1. Construct the 98% confidence interval for the mean per capita income in thousands of dollars. Round your answers to one decimal place.
Answer:
= ( $18.2, $18.8)
Therefore, the 98% confidence interval (a,b) = ( $18.2, $18.8)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = $18.50
Standard deviation r = $6.10
Number of samples n = 2253
Confidence interval = 98%
z(at 98% confidence) = 2.33
Substituting the values we have;
$18.5+/-2.33($6.1/√2253 )
$18.5+/-2.33($0.128513644290)
$18.5+/-$0.299436791196
$18.5+/-$0.3
= ( $18.2, $18.8)
Therefore at 98% confidence interval (a,b) = ( $18.2, $18.8)
The Hartnett Corporation manufactures baseball bats with Pudge Rodriguez's autograph stamped on them. Each bat for $35 and has a variable cost of $22. there are $97,500 in fixed costs involved in the production process.
Find the sales (in units) needed to earn a profit of $300,000.
Answer:
Find the sales (in units) needed to earn a profit of $262,500
Step-by-step explanation:
hope this is helpful to you bro
A delivery truck is transporting boxes of two sizes: large and small. The large boxes weigh 50 pounds each, and the small boxes weigh 35 pounds each. There are 115 boxes in all. If the truck is carrying a total of 5000 pounds in boxes, how many of each type of box is it carrying?
Answer:
Step-by-step explanation:
First, "boxes of two sizes" means we can assign variables:
Let x = number of large boxes
y = number of small boxes
"There are 115 boxes in all" means x + y = 115 [eq1]
Now, the pounds for each kind of box is:
(pounds per box)*(number of boxes)
So,
pounds for large boxes + pounds for small boxes = 4125 pounds
"the truck is carrying a total of 4125 pounds in boxes"
(50)*(x) + (25)*(y) = 4125 [eq2]
It is important to find two equations so we can solve for two variables.
Solve for one of the variables in eq1 then replace (substitute) the expression for that variable in eq2. Let's solve for x:
x = 115 - y [from eq1]
50(115-y) + 25y = 4125 [from eq2]
5750 - 50y + 25y = 4125 [distribute]
5750 - 25y = 4125
-25y = -1625
y = 65 [divide both sides by (-25)]
There are 65 small boxes.
Put that value into either equation (now, which is easier?) to solve for x:
x = 115 - y
x = 115 - 65
x = 50
There are 50 large boxes.
Check (very important):
Is 50+65 = 115 ? [eq1]
115 = 115 ?yes
Is 50(50) + 25(65) = 4125 ?
2500 + 1625 = 4125 ?
4125 = 4125 ? ye
Can someone please help me fast
Answer:
x = 3.5
Step-by-step explanation:
Since the triangles are similar we can use ratios to solve
4 7
------ = ------
(4+2) ( 7+x)
Using cross products
4(7+x) = 7*(4+2)
Distribute
28+4x = 42
Subtract 28 from each side
4x = 42-28
4x= 14
Divide by 4
4x/4 = 14/4
x = 7/2
Merely needs to add enough water to 11 gallons of an 18% detergent solution to make 12% detergent solution which equation can she used to find g the number of gallon of water she should add?
1 × 18/100 = 12/100(g+11), is the equation. The answer is 12/100 gallons
Find the exact length of the third side. (Pythagorean Theorem)
Answer:
3 sqrt(5) =c
Step-by-step explanation:
We can use the pythagorean theorem
a^2 + b^2 = c^2
3^2 + 6^2 = c^2
9+36 = c^2
45 = c^2
Take the square root of each side
sqrt(45) = sqrt(c^2)
sqrt(9)sqrt(5) = c
3 sqrt(5) =c
a 680g patient comes in with diarrhea. the doctor orders anti-diarrhea medication at a dosage of 15 mcg/kg TID x 3 days. rhye medication concentration 50mcg/ml. What is the patients dose in MCG? What is the total volume of medication you will send home?
Answer:
dose in MCG = 10.2 mcg
Total volume to be sent home = 1.836 ml (1836μl)
Step-by-step explanation:
weight of patient = 680g
dosage in mcg of medication = 15mcg/kg
This means that
for every 1kg weight, 15mcg is given,
since 1kg = 1000g, we can also say that for every 1000g weigh, 15mcg is given.
1000g = 15mcg
1g = 15/1000 mcg = 0.015 mcg
∴ 680g = 0.015 × 680 = 10.2 mcg
Dosage in MCG = 10.2 mcg
Next, we are also told ever ml volume of the drug contains 50 mcg weight of the drug (50mcg/ml). This can also be written as:
50mcg = 1 ml
1 mcg = 1/50 ml = 0.02 ml
∴ 10.2 mcg = 10.2 × 0.02 = 0.204 ml
since the medication is to be taken TID (three times daily) for 3 days, the total number of times the drug is to be taken = 9 times.
therefore, the total volume required = 0.204 × 9 = 1.836 ml (1836 μl)
Given that y = 1.5 at x = -2. Find the function y = f(x) such that
dy/dx=√(4y+3)/x²
Answer:
[tex]y=\frac{(-\frac{4}{x}+1)^2-3 }{4}[/tex]
Step-by-step explanation:
We are given the following information. y have the point [tex](-2,\frac{3}{2} )[/tex] and [tex]\frac{dy}{dx} =\frac{\sqrt{4y+3} }{x^2}[/tex]
First, we need to separate the variables to their respective sides
[tex]\frac{1}{\sqrt{4y+3} } dy=\frac{1}{x^2} dx[/tex]
Now, we need to integrate each side
[tex]\int \frac{1}{\sqrt{4y+3} } dy=\int\frac{1}{x^2} dx[/tex]
But first, let us rewrite these functions
[tex]\int (4y+3)^{-\frac{1}{2} } dy=\int x^{-2} dx[/tex]
Before we can integrate, we need to have the hook for the first function. When we integrate [tex](4y+3)^{-\frac{1}{2} }[/tex], we must have a lone 4 within the integral as well.
[tex]\frac{1}{4} \int4 (4y+3)^{-\frac{1}{2} } dy=\int x^{-2} dx[/tex]
Now we can integrate each side to get
[tex]\frac{1}{4} \sqrt{4y+3} =-\frac{1}{x} + c[/tex]
Now is the best time to use the given point in order to find the value of c.
[tex]\frac{1}{4} \sqrt{4(\frac{3}{2}) +3} =-\frac{1}{-2} + c\\\\\frac{1}{4}\sqrt{6+3} =\frac{1}{2} +c \\\\\frac{3}{4}=\frac{1}{2} +c\\ \\c=\frac{1}{4}[/tex]
Now we can plug in our value for c and then solve for y
[tex]\frac{1}{4} \sqrt{4y+3} =-\frac{1}{x} + \frac{1}{4} \\\\\sqrt{4y+3}=-\frac{4}{x} +1\\ \\4y+3=(-\frac{4}{x} +1)^2\\\\4y=(-\frac{4}{x} +1)^2-3\\\\y=\frac{(-\frac{4}{x} +1)^2-3}{4}[/tex]
Which formula can be used to describe the sequence? - 2/3, -4, -24, -144
Answer:
They are all multiplied by 6
Answer:
Geometric sequence.
Step-by-step explanation:
Here are the terms :
-2/3, -4, -24, -144
Now the first term T1 = -2/3
The second Term T2 = -4
But T2/T1 = -4÷ -2/3 = -4 x -3/2 = 6
Similarly Term 3, T3 = -24
T3/T2 = -24/-4= 6
Hence the expression is a geometric sequence.
a×r^(n-1); a is the first term
r is the common ratio 6
n is the number of terms.
An aeroplane X whose average speed is 50°km/hr leaves kano airport at 7.00am and travels for 2 hours on a bearing 050°. It then changes its course and flies on a bearing 1200 to an airstrip A. Another aeroplane Y leaves kano airport at 10.00am and flies on a straight course to the airstrip A. both planes arrives at the airstrip A at 11.30am. calculate the average speed of Y to three significant figures. the direction of flight Y to the nearest degree
Answer:
(a)123 km/hr
(b)39 degrees
Step-by-step explanation:
Plane X with an average speed of 50km/hr travels for 2 hours from T (Kano Airport) to point U in the diagram.
Distance = Speed X Time
Therefore: Distance from T to U =50km/hr X 2 hr =100 km
It moves from Point U at 9.00 am and arrives at the airstrip A by 11.30am.
Distance, UA=50km/hr X 2.5 hr =125 km
Using alternate angles in the diagram:
[tex]\angle U=110^\circ[/tex]
(a)First, we calculate the distance traveled, TA by plane Y.
Using Cosine rule
[tex]u^2=t^2+a^2-2ta\cos U\\u^2=100^2+125^2-2(100)(125)\cos 110^\circ\\u^2=34175.50\\u=184.87$ km[/tex]
Plane Y leaves kano airport at 10.00am and arrives at 11.30am
Time taken =1.5 hour
Therefore:
Average Speed of Y
[tex]=184.87 \div 1.5\\=123.25$ km/hr\\\approx 123$ km/hr (correct to three significant figures)[/tex]
b)Flight Direction of Y
Using Law of Sines
[tex]\dfrac{t}{\sin T} =\dfrac{u}{\sin U}\\\dfrac{125}{\sin T} =\dfrac{184.87}{\sin 110}\\123 \times \sin T=125 \times \sin 110\\\sin T=(125 \times \sin 110) \div 184.87\\T=\arcsin [(125 \times \sin 110) \div 184.87]\\T=39^\circ $ (to the nearest degree)[/tex]
The direction of flight Y to the nearest degree is 39 degrees.
What is the answer to this question?
Answer:it is b
Step-by-step explanation:
The area of a circle is 153.86 square meters. What is the diameter of the circle? Use 3.14 for π.
Answer:
Option (2). 14 m
Step-by-step explanation:
Formula to get the area of a circle 'A' = [tex]\pi r^{2}[/tex]
where r = radius of the circle
Given in the question,
Area of the circle = 153.86 square meters
By putting the values in the formula,
153.86 = πr²
r = [tex]\sqrt{\frac{153.86}{\pi } }[/tex]
r = [tex]\sqrt{49}[/tex]
r = 7 meters
Diameter of circle = 2 × (radius of the circle)
= 2 × 7
= 14 meters
Therefore, diameter of the circle is 14 meters.
Option (2) is the answer.
Answer:
14m
Step-by-step explanation:
which of the points shown below are on the line given by the equation y=3x?check all that apply.
Point A: (1,3)
Point B: (3,1)
Point C: (3,-1)
Point D: (-1,-3)
Answer:
Point A: (1,3)Point D: (-1,-3)Step-by-step explanation:
The value of y in the (x, y) pair must be 3 times the value of x if the point is to be on the line. That is the case for points A, D.
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
We can use the zero product property to solve
x+3 =0 x-8 =0
x= -3 x=8
Answer:
x=8
Step-by-step explanation:
g You flip the coin 200 times and observed 80 Heads. Recall from the problem Hypothesis Testing: A Sample Data Set of Coin Flips I in the previous lecture that the value of the test statistics Tn for this data set is T200=2.83 . If the test ψ=1(Tn>qα/2) is designed to have asymptotic level 5% , would you reject or fail to reject the null hypothesis H0:p∗=1/2 for this data set?
Answer:
Step-by-step explanation:
To be able to draw a conclusion from the data given, lets find out the p value using the t score and this will be used to make a conclusion.
If the p value is less than 0.05 then, we will reject the null but if otherwise we will fail to reject the null.
Using a p value calculator with a t score of 2.83, significance level 0.05 and the test is a two tailed test, the p value is 0.004655 which is less than 0.05 and the result is significant.
This we will reject the null hypothesis H0:p∗=1/2 for this data set.
Is (-3,2) a solution of 7x+9y>-3
Yes or no
Please help :))
Answer:
(-3,2) is not a solution.
Step-by-step explanation:
The solution of a linear inequality in two variables like [tex]Ax + By > C[/tex] is an ordered pair [tex](x, y)[/tex] that produces a true statement when the values of x and y are substituted into the inequality.
To find if (-3,2) is a solution of [tex]7x+9y>-3[/tex], you must substitute this point into the inequality.
[tex]7\left(-3\right)+9\left(2\right)>-3\\\\-21+18>-3\\\\-3>-3[/tex]
Because -3 is not greater than -3, (-3,2) is not a solution.
Answer:
No
Step-by-step explanation:
Khan academy
Please answer this correctly
Answer:
pic wont load
Step-by-step explanation:
Answer:
The quarter circle's area is 38.47 yard²
Step-by-step explanation:
The area of a full circle is pi * r ²
The area of a quarter circle is 1/4 * pi * r ²
Given:
Use 3.14 for pi
Round to the nearest hundredths.
Perimeter of quarter circle is 24.99 yards
For r you must leave it as 'r' because we do not know it for now...
1. Circumference of a full circle = 2* pi * r
2. 1/4 * ( 2 * pi * r )
1/4 * ( 2 * 3.14 * r )
1/2 * 3.14 * r
1.57 * r
3 Since r = 'r'
We have to 2 sides running from the centre of the 'pie' to the left and right of the quarter circle which both have a length of exactly 'r'. So you just add 2 * r.
4. The outcome of step 2 + step 3 is the perimeter of quarter circle, which was given as 24.99 inch
1.57 * r + 2 * r = 24.99
( 1.57 + 2 ) * r = 24.99
3.57 * r = 24.99
Divide left and right of the = sign by 3.57
3.57 / 3.57 * r = 24.99 / 3.57
1 * r = 24.99 / 3.57
r = 7
The area of a quarter circle is 1/4 * pi * r ²
1/4 * pi * 7²
1/4 * 49 * pi
49/4 * pi
49/4 * 3.14
38.465
Round to the nearest hundredths gives 38.47 yard²
The quarter circle's area is 38.47 yard²
How many pound are in 28 ounces
Answer:
1.75
Step-by-step explanation:
Divide the ounces by 16 to get the value.
11. A square with sides
3/8
inch has a total area of:
Answer:
[tex](\frac{3}{8}\,in )^2=\frac{9}{64} \,in^2=0.140625\,\,i^2[/tex]
Step-by-step explanation:
Recall that the formula for the area of a square of side L is: [tex]Area=L^2[/tex]
Therefore, for this case:
[tex]Area=L^2\\Area = (\frac{3}{8} \,in)^2\\Area=\frac{9}{64} \,\,in^2\\Area=0.140625\,\,in^2[/tex]
what is the midpoint of the segment shown below?
(1, 2) (1,-5)
A. (1, -3/2)
B. (2, -3/2)
C. (2, -3)
D. (1, -3)
Answer:
The answer is A (1,-3/2)
Step-by-step explanation:
Add both x coordinates, divide by 2
Add both y coordinates, divide by 2
What is the distance from point N to line LM in the figure below?
Answer:
The correct answer would be F. 7.8
Step-by-step explanation:
the line is more or less a reflection of segment ON
so they are more or less the same.
I hope this helped you!
find the slope of a line parallel to y=(2/5)x + (4/5)
Answer:
So if a line was parallel it would have same slope. You can search up what slope-intercept form means. But if you have an equation like this:
y = mx+b
The slope will be m. Your question is written in the form. 2/5 = m.
The slope is 2/5
The y-intercept is 4/5
Answer:
m=2/5
Step-by-step explanation:
Lines that are parallel have the exact same slope.
We have an equation in point slope form.
y=mx+b
where m is the slope and b is the y-intercept.
The slope is the number being multiplied by x. In the equation
y=2/5x+4/5
2/5 and x are being multiplied. Therefore, 2/5 is the slope. A line that is parallel will have the same slope of 2/5.
g A cannonball is shot with an initial speed of 62 meters per second at a launch angle of 25 degrees toward a castle wall that is 260 meters away. If the wall is 20 meters tall, how high off the ground will the cannonball hit
Answer:
h = 16.23 m
The cannonball will hit the wall at 16.23m from the ground.
Step-by-step explanation:
Given;
Initial speed v = 62m/s
Angle ∅ = 25°
Horizontal distance d = 260 m
Height of wall y = 20
Resolving the initial speed to vertical and horizontal components;
Horizontal vx = vcos∅ = 62cos25°
Vertical vy = vsin∅ = 62cos25°
The time taken for the cannon ball to reach the wall is;
Time t = horizontal distance/horizontal speed
t = d/vx (since horizontal speed is constant)
t = 260/(62cos25°)
t = 4.627 seconds.
Applying the equation of motion;
The height of the cannonball at time t is;
h = (vy)t - 0.5gt^2
Acceleration due to gravity g = 9.81 m/s
Substituting the given values;
h = 62sin25×4.627 - 0.5×9.81×4.627^2
h = 16.2264134736
h = 16.23 m
The cannonball will hit the wall at 16.23m from the ground.
A package of 10 batteries is checked to determine if there are any dead batteries. Four batteries are checked. If one or more are dead, the package is not sold. What is the probability that the package will not be sold if there are actually three dead batteries in the package
Answer:
There is a probability of 76% of not selling the package if there are actually three dead batteries in the package.
Step-by-step explanation:
With a 10-units package of batteries with 3 dead batteries, the sampling can be modeled as a binomial random variable with:
n=4 (the amount of batteries picked for the sample).p=3/10=0.3 (the proportion of dead batteries).k≥1 (the amount of dead batteries in the sample needed to not sell the package).The probability of having k dead batteries in the sample is:
[tex]P(x=k) = \dbinom{n}{k} p^{k}q^{n-k}[/tex]
Then, the probability of having one or more dead batteries in the sample (k≥1) is:
[tex]P(x\geq1)=1-P(x=0)\\\\\\P(x=0) = \dbinom{4}{0} p^{0}q^{4}=1*1*0.7^4=0.2401\\\\\\P(x\geq1)=1-0.2401=0.7599\approx0.76[/tex]
Antoinette needs to solve this system of equations by graphing. Which statements explain how she should graph the equations? Check all that apply.
Answer:
see below
Step-by-step explanation:
In my opinion, Antoinette should make use of a graphing calculator to find the solution. (second attachment)
__
Slope-intercept form can be useful for graphing, so it often works well to start with equations in that form. If that is Antoinette's strategy, she should rewrite the first equation to that form. The second equation is already in slope-intercept form.
In doing that rewrite, she will want to get the y-term on one side of the equal sign by itself. She can do that by subtracting 2x from the first equation:
-7y = -2x +56
As a final step in her rewrite, she would divide by -7 to get ...
y = 2/7x +56
This 2nd equation has a positive slope of 2/7. The slope of the second equation is similarly the x-coefficient, -2.5. Neither is 4 and they have different signs.
The appropriate answer choices are shown checked below.
Answer:
B and D
Step-by-step explanation:
I got it right m8. Good day
A linear track begins at 0 meters and has a total distance of 100 meters to the finish line. Juliet starts at the 100 meter mark while practicing for a race. After running 45 meters how far is she from the beginning of the track?
Answer:
It’s D, 55.
Step-by-step explanation:
After running 45 meters, Juliet runs 55 meters from the beginning of the track
If 25% of a number is 100, what is the number?
OA.
50
B.
100
O C.
150
D.
200
o E.
400
Answer:
E. 400
Step-by-step explanation:
So this is how we set this up, and how we solve
[tex]0.25x=100\\x=100/0.25\\x=400[/tex]
Hope this helps!
So you are solving for circumference of a quarter circle: [tex]\frac{1}{4}2 \pi r[/tex]
r= 28
[tex]\pi=3.14[/tex]
[tex]\frac{1}{4}2(87.92)=\\43.96[/tex]
PLEASE HELP ME GUYS!!
Answer:
[tex]\frac{7}{3}[/tex]
Step-by-step explanation:
csc(Ф) is equivalent to the inverse of sin(Ф)
[tex]csc = \frac{1}{sin}[/tex]Since sin(Ф) = 3/7, the inverse of this would be 7/3
So, [tex]csc = \frac{1}{\frac{3}{7} }=\frac{7}{3}[/tex]