A soccer league has 180 players. Of those players 50% are boys. How many boys are in the soccer league?

Answer:

Step-by-step explanation:

This is a test of 2 independent groups. Let μ1 be the mean dissolution time for disk-shaped ibuprofen tablets and μ2 be the mean dissolution time for oval-shaped ibuprofen tablets.

The random variable is μ1 - μ2 = difference in the mean dissolution time for disk-shaped ibuprofen tablets and the mean dissolution time for oval-shaped ibuprofen tablets.

We would set up the hypothesis.

a) The null hypothesis is

H0 : μ1 = μ2 H0 : μ1 - μ2 = 0

The alternative hypothesis is

H1 : μ1 ≠ μ2 H1 : μ1 - μ2 ≠ 0

This is a two tailed test.

For disk shaped,

Mean, x1 = (269.0 + 249.3 + 255.2 + 252.7 + 247.0 + 261.6)/6 = 255.8

Standard deviation = √(summation(x - mean)²/n

n1 = 6

Summation(x - mean)² = (269 - 255.8)^2 + (249.3 - 255.8)^2 + (255.2 - 255.8)^2+ (252.7 - 255.8)^2 + (247 - 255.8)^2 + (261.6 - 255.8)^2 = 337.54

Standard deviation, s1 = √(337.54/6) = 7.5

For oval shaped,

Mean, x2 = (268.8 + 260 + 273.5 + 253.9 + 278.5 + 289.4 + 261.6 + 280.2)/8 = 270.7375

n2 = 8

Summation(x - mean)² = (268.8 - 270.7375)^2 + (260 - 270.7375)^2 + (273.5 - 270.7375)^2+ (253.9 - 270.7375)^2 + (278.5 - 270.7375)^2 + (289.4 - 270.7375)^2 + (261.6 - 270.7375)^2 + (280.2 - 270.7375)^2 = 991.75875

Standard deviation, s2 = √(991.75875/8) = 11.1

b) Since sample standard deviation is known, we would determine the test statistic by using the t test. The formula is

(x1 - x2)/√(s1²/n1 + s2²/n2)

Therefore,

t = (255.8 - 270.7375)/√(7.5²/6 + 11.1²/8)

t = - 3

c) The formula for determining the degree of freedom is

df = [s1²/n1 + s2²/n2]²/(1/n1 - 1)(s1²/n1)² + (1/n2 - 1)(s2²/n2)²

df = [7.5²/6 + 11.1²/8]²/[(1/6 - 1)(7.5²/6)² + (1/8 - 1)(11.1²/8)²] = 613.86/51.46

df = 12

We would determine the probability value from the t test calculator. It becomes

p value = 0.011

d) Since alpha, 0.05 > than the p value, 0.011, then we would reject the null hypothesis. Therefore, we can conclude that at 5% significance level, the mean dissolve times differ between the two shapes

Answer:

We use the binomial distribution to describe this situation.

The mean number of phone sales is 749.7 with a standard deviation of 15.

Step-by-step explanation:

For each shopper, there are only two possible outcomes. Either they plan to purchase the newly released smart phone, or they do not. Each customer is independent of other customers. So we use the binomial distribution to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

The standard deviation of the binomial distribution is:

[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]

Fifty random shoppers at an electronics store have been interviewed and 35 of them intend to purchase a newly released smart phone.

This means that [tex]p = \frac{35}{50} = 0.7[/tex]

What are its mean and standard deviation of phone sales if we are concerned about 1071 shoppers that day

1071 shoppers, so [tex]n = 1071[/tex]

Mean

[tex]E(X) = 1071*0.7 = 749.7[/tex]

Standard deviation

[tex]\sqrt{V(X)} = \sqrt{1071*0.7*0.3} = 15[/tex]

The mean number of phone sales is 749.7 with a standard deviation of 15.

Answer:

16.

Step-by-step explanation:

since given the radius and the formula of the circumference of a circle is 2pie*r

Answer:

5

Step-by-step explanation:

Answer:

x = 1/2 , y = 6

Explanation:

Step 1 - Align the equations and multiply the second row by 2

4x + 3y = 20

2x + y = 7

4x + 3y = 20

4x + 2y = 14

Step 2 - Subtract them both

4x + 3y = 20

4x + 2y = 14

y = 6

So, y = 6

Step 3 - Substitute y into the first equation

4x + 3y = 20

4x + 3(6) = 20

4x + 18 = 20

Step 4 - Subtract 18 from both sides

4x + 18 = 20

4x + 18 - 18 = 20 - 18

4x = 2

Step 5 - Divide both sides by 4

4x = 2

4x / 4 = 2 / 4

x = 2/4

So, x = 1/2

Answer:

The trip will take 36 minutes.

Step-by-step explanation:

This question can be solved using a rule of three.

The boat maintains a constant speed of 15 knots (nautical miles per hour). How many minutes it will take to return to its home port 9 nautical miles away?

So in 60 minutes, 15 nautical miles. How many minutes for 9 nautical miles?

60 minutes - 15 nautical miles

x minutes - 9 nautical miles

[tex]15x = 60*9[/tex]

[tex]x = \frac{60*9}{15}[/tex]

[tex]x = 36[/tex]

The trip will take 36 minutes.

80km / 48 min = 1 2/3 km per minute.

1 2/3 km per minute x 60 minutes(1 hour) = 100 km per hour

Answer:

3.43

Step-by-step explanation:

3 is the whole number and 43 out of 100 is a standard fraction that can simply be stated as 0.43. Hope this helps!

Answer:

3.43

Step-by-step explanation:

Used calculator.

Answer:

225 I believe because if he has $90 that is 2/5 so add another 90 whitch is 2/5 as well and divide 90 by 2 and to get 45 which all adds up to 225

Answer:

[tex]\frac{14}{125}\times 100=11.2\%[/tex]

Answer:

28 and 7

35

Step-by-step explanation:

The area of a triangle is base*height/2, no matter the shape.

So the big one is 8*7/2 = 28 in²

And the little one is 2*7/2 = 7 in²

The total trapezoid therefore has an area of 28+7=35 in²

Answer:

B

Step-by-step explanation:

[tex]\dfrac{3}{7}\times 0.1 \div \dfrac{5}{21}= \\\\\\\dfrac{3}{7}\times \dfrac{1}{10}\times \dfrac{21}{5}= \\\\\\\dfrac{3\times 1 \times 21}{7 \times 10 \times 5}=\\\\\\\dfrac{63}{350}=\\\\\\\dfrac{9}{50}[/tex]

Therefore, the correct answer is choice B. Hope this helps!

Answer:

The answer to your question is 9/50

Answer:

[tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]

Step-by-step explanation:

The objective is to find the moment generating  function of  [tex]M_{X+Y}(t) \ of \ X+Y[/tex].

We are being informed that the fair die is rolled twice;

So; X to be the value for the  first roll

Y to be the value of the second roll

The outcomes  of X are:  X = {1,2,3,4,5,6}

Where ;

[tex]P (X=x) = \dfrac{1}{6}[/tex]

The outcomes  of Y are:  y = {1,2,3,4,5,6}

Where ;

[tex]P (Y=y) = \dfrac{1}{6}[/tex]

The outcome of Z = X+Y

[tex]= \left[\begin{array}{cccccc}(1,1)&(1,2)&(1,3)&(1,4)&(1,5)&(1,6)\\ (2,1)&(2,2)&(2,3)&(2,4)&(2,5)&(2,6)\\ (3,1)&(3,2)&(3,3)&(3,4)&(3,5)&(3,6) \\ (4,1)&(4,2)&(4,3)&(4,4)&(4,5)&(4,6) \\ (5,1)&(5,2)&(5,3)&(5,4)&(5,5)&(5,6) \\ (6,1)&(6,2)&(6,3)&(6,4)&(6,5)&(6,6) \end{array}\right][/tex]

= [2,3,4,5,6,7,8,9,10,11,12]

Here;

[tex]P (Z=z) = \dfrac{1}{36}[/tex]

∴ the moment generating function [tex]M_{X+Y}(t) \ of \ X+Y[/tex]is as follows:

[tex]M_{X+Y}(t) \ of \ X+Y[/tex] = [tex]E(e^{t(X+Y)}) = E(e^{tz})[/tex]

⇒ [tex]\sum \limits^{12}_ {z=2 } et ^z \ P(Z=z)[/tex]

= [tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]

Answer:

-15

Step-by-step explanation:

The solution of expression for x = - 4 is,

⇒ - 15

We have to given that,

An expression is,

⇒ 2x - 7

Now, We can simplify the expression for x = - 4 as,

An expression is,

⇒ 2x - 7

Plug x = - 4;

⇒ 2 × - 4 - 7

⇒ - 8 - 7

⇒ - 15

Thus, The solution of expression for x = - 4 is,

⇒ - 15

Learn more about the equation visit:

brainly.com/question/28871326

#SPJ6

Answer:

94 more students should be included in the sample.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1-0.99}{2} = 0.005[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].

So it is z with a pvalue of [tex]1-0.005 = 0.995[/tex], so [tex]z = 2.575[/tex]

Now, find the margin of error M as such

[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

How many students we need to sample to be 99% sure that the sample mean x is within 1 semester hour of the population mean?

We need to survey n students.

n is found when M = 1.

We have that [tex]\sigma = 4.7[/tex]

So

[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]

[tex]1 = 2.575*\frac{4.7}{\sqrt{n}}[/tex]

[tex]\sqrt{n} = 2.575*4.7[/tex]

[tex](\sqrt{n})^{2} = (2.575*4.7)^{2}[/tex]

[tex]n = 146.47[/tex]

Rounding up

147 students need to be surveyed.

How many more students should be included...?

53 have already been surveyed

147 - 53 = 94

94 more students should be included in the sample.

Answer:

True

Step-by-step explanation:

Answer: The measure of angle B is 31 degrees.

Step-by-step explanation:

180 -149 = 31

Answer:

31 degrees

Step-by-step explanation:

We can see that 149 degrees and b are on a line. If they are next to each other they are called adjacent angles. There is a rule that adjacent angles add up to 180 degrees. So we subtract 149 from 180 and we get 31 degrees for angle b.

Hope this helps! :)

Answer:

D. (250, 80)

Step-by-step explanation:

a) Outliers are values that "lie outside" the other values in a dataset, because their values are "far away" from the main group of data.

b) In this case, the values of A, B, and C have ratios of their coordinates of about 2.5, but the coordinate ratio of D is more than 3.  This makes it to lie far away from the group of data, and therefore an outliner.

c) The Ratios of the Coordinate Values are calculated as follows: A = 2.5 (150/60), B = 2.5 (50/20), C = 2 (200/100), while D = 3.125 (250/80).

Answer:

14m

Step-by-step explanation:

The area of a circle is given by

A = pi r^2

153.86 = 3.14 r^2

Divide each side by  3.14

153.86 /3.14 = r^2

49 = r^2

Take the square root of each side

sqrt(49) = sqrt(r^2)

7 = r

We want the diameter which is twice the radius

d = 2r

d =2*7

d =14

Answer:

I just wanted to add on it is 14 i tried it on savaas and it worked

Step-by-step explanation:

Answer:

I think l

Step-by-step explanation:

first add 96 and4 then 2 I think

Answer:

When x = -1/4 and when x = -15/4

Step-by-step explanation:

The x intercept will be when f(x)=0, so

0 = 4|x+2| -7

7 = 4|x+2|

|x+2|=7/4 here you have to cases

case 1

x+2=7/4

x=7/4-2

x=-1/4 = -0.25

case 2

x+2 = -7/4

x = -2-7/4

x = -15/4 = -3.75

Answer:

78/100000

Hope it helps you

Answer:

270 inches³

Step-by-step explanation:

Volume of carton = wlh

Where w is width, h is height and length is l

V = (9)(5)(6)

V = 270 inches³

Answer:

L = 3/4

Option A. The Root Test says that the series converges absolutely.

Step-by-step explanation:

By using the root test equation given in the question. L = 3/4

Since L < 1, the series converges absolutely.

For clarity of expression, the detailed calculation is contained in the attached file. Check the file attached for the complete calculation to this question.

Answer:

About 22.2 square feet

Step-by-step explanation:

First, you need to find the area of the full circle. The area of a circle is \pi r^2, which in this case is:

[tex]\pi r^2 = \pi \cdot 7.13^2\approx 159.628[/tex]

Now, since the sector is only 50 out of the total 360 degrees in a circle, you need to multiply this value by 50/360, which yields and area of about 22.2 square feet. Hope this helps!

Answer:

Plot the y-intercept at (0, 2). Plot your second point at (-1, -1).

Step-by-step explanation:

I attached an image of what the finished graph should look like when you press done. *rotate the image so the grey is on the bottom*