At a school, 40% of the sixth-grade students said that hip-hop is their favorite kind of music. If 68 sixth-grade students prefer hip hop music, how many sixth-grade students are at the school?

Answer:

0.7517 = 75.17% probability that the mean IQ of the 3 North Catalina students is at least 5 points higher than the mean IQ of the 3 Chapel Mountain students

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Subtraction of normal variables:

When we subtract normal variables, the mean is the subtraction of the means, while the standard deviation is the square root of the sum of the variances.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

North Catalina:

Population has mean 130 and standard deviation 8 points. Sample of 3. This means that:

[tex]\mu_{N} = 130, s_{N} = \frac{8}{\sqrt{3}} = 4.6188[/tex]

Chapel Mountain:

Population has mean 120 and standard deviation 10 points. Sample of 3. This means that:

[tex]\mu_{C} = 120, s_{C} = \frac{10}{\sqrt{3}} = 5.7735[/tex]

What is the probability that the mean IQ of the 3 North Catalina students is at least 5 points higher than the mean IQ of the 3 Chapel Mountain students?

We want that: [tex]N - C > 5[/tex]

Distribution N - C:

The mean is:

[tex]\mu = \mu_N - \mu_C = 130 - 120 = 10[/tex]

The standard deviation is:

[tex]s = \sqrt{s_N^2+s_C^2} = \sqrt{4.6188^2+5.7735^2} = 7.3937[/tex]

This probability is 1 subtracted by the pvalue of Z when X = 5. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{5 - 10}{7.3937}[/tex]

[tex]Z = -0.68[/tex]

[tex]Z = -0.68[/tex] has a pvalue of 0.2483

1 - 0.2483 = 0.7517

0.7517 = 75.17% probability that the mean IQ of the 3 North Catalina students is at least 5 points higher than the mean IQ of the 3 Chapel Mountain students

Answer:

24.5

Step-by-step explanation:

Answer:

A.) 4/25

Step-by-step explanation:

Answer:

x = 49

Step-by-step explanation:

This is an inverse relationship and it implies that, an increase in the value of one variable results in a subsequent decrease in the value of another variable.

Given the mathematical expression and data;

y = 1/√x

y = 7 and x = 64

First of all, we would find the constant of proportionality, k;

y = k/√x

7 = k/√64

7 = k/8

k = 7 * 8

Constant, k = 56

Now, to find the value of x when y = 8

y = k/√x

Substituting the values, we have;

8 = 56/√x

Cross-multiplying, we have;

8 * √x = 56

√x = 56/8

√x = 7

Taking the square of both sides, we have;

(√x)² = 7²

x = 49

Answer:

Rate.

Step-by-step explanation:

Answer:

m∠3 = 119°

Step-by-step explanation:

All the angles must equal 360° when added together. You have two known angles that are right next to each other. If you add m∠1 and m∠2, 119 + 61, it is equal to 180°. This means that m∠3 and m∠4 must be equal to 180° as well and since there are only two lines, it is safe to assume that opposing angles are the same so m∠1 = m∠3 and m∠2 = m∠4.

Answer:

K12 answer

Step-by-step explanation:

Answer:

becuase 2*3 is 6, and 2*4 is 8, and when you simplfy it is 1 and 1/2, which in decimal form is 1.5, making it less than 2

Answer:

Is 2/4 smaller than 2/3? These are the same questions with one answer.

To get the answer, we first convert each fraction into decimal numbers. We do this by dividing the numerator by the denominator for each fraction as illustrated below:

2/4 = 0.5

2/3 = 0.667

Then, we compare the two decimal numbers to get the answer.

0.5 is less than 0.667.

Therefore, 2/4 is less than 2/3 and the answer to the question "Is 2/4 less than 2/3?" is yes.

i  think this will help

Answer:

The 90% confidence interval estimate of the mean of the population is between 6627 and 6941.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used 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 = 15 - 1 = 14

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 14 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.761

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.761\frac{345}{\sqrt{15}} = 157[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 6784 - 157 = 6627

The upper end of the interval is the sample mean added to M. So it is 6784 + 157 = 6941

The 90% confidence interval estimate of the mean of the population is between 6627 and 6941.

Answer:

$2672.20

Step-by-step explanation:

2300(1+(0.03)/(365))^(5*365)

=$2672.20

Answer:

Communitative Property

Step-by-step explanation:

:P

Answer:

Step-by-step explanation:

x+y = 9

x-y = 60

-----------

2x = 69

x = 34.5

y = 9-x = -25.5

smaller number: -25.5

larger number: 34.5

Answer:

Frame A width = 6.67 inches

Frame B width = 6 inches

Step-by-step explanation:

WA = width of frame A

WB = width of frame B

(WA)(6.75) = 45

WA = 6.67

(WB)(7.5) = 45

WB = 6

Answer: Neither

Step-by-step explanation:

Answer:

I think its B or C

Step-by-step explanation:

Answer: 300

Step-by-step explanation:

Answer:

300

Step-by-step explanation:

If all terms are negative then the result will come out positive.

Answer:

90 I hope this helps good luck

Answer:

Its 90 degrees but I am not sure what you are asking

Step-by-step explanation:

Answer:

Step-by-step explanation:

y = 4x + 1

Slope of line = 4

Slope of perpendicular to line = -¼

Point-slope equation for line of slope -¼ that passes through (12, -7):

y+7= -¼(x-12)

Answer: 8 dinos

Step-by-step explanation:

there are 4 boxes and 5 handfuls in each. divide 160 by 4 and divide that, 40, by 5 to get 8

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Answer:

a. committed a type 1 error

Step-by-step explanation:

The correct option is - a. committed a type 1 error

Reason -

Type 1 error occurs  when a true null Hypothesis is rejected

Type 2 error occurs when a false null Hypothesis is accepted

Now,

Let us state that,

The null hypothesis and alternate hypothesis is

H0 : There is no difference between the mean lifetimes of the new and old designs

H1 : There is a difference between the mean lifetimes of the new and old designs

Now,

As there is no difference between the mean lifetimes of the new and old designs.

⇒ The null hypothesis is true.

But p value suggests that null hypothesis should be rejected

∴

We have committed a Type 1 error that is rejecting a true null hypothesis.

So,

The correct option is - a. committed a type 1 error

The answer is A) 60°

Step-by-step explanation:

It's reflecting

Answer:

You must survey 784 air passengers.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

Assume that nothing is known about the percentage of passengers who prefer aisle seats.

This means that [tex]\pi = 0.5[/tex], which is when the largest sample size will be needed.

Within 3.5 percentage points of the true population percentage.

We have to find n for which M = 0.035. So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.035 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]

[tex]0.035\sqrt{n} = 1.96*0.5[/tex]

[tex]\sqrt{n} = \frac{1.96*0.5}{0.035}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96*0.5}{0.035})^2[/tex]

[tex]n = 784[/tex]

You must survey 784 air passengers.

Answer:

Step-by-step explanation:

x% of 40 = 22

(x/100)×40 = 22

x = 22×100/40 = 55

22 is 55% of 40

:::::

35% of 60 = 0.35×60 = 21

Answer:

[tex]\huge\boxed{55\%}\\\boxed{21}[/tex]

Step-by-step explanation:

22 is what percent of 40?

[tex]\dfrac{22}{40\!\!\!\!\diagup}\cdot100\!\!\!\!\diagup\%=\dfrac{22\cdot10}{4}\%=\dfrac{11\cdot5}{1}\%=55\%[/tex]

[tex]p\%=\dfrac{p}{100}\\\\35\%=\dfrac{35}{100}=0.35\\\\35\%\ of\ 60\to \dfrac{35}{100\!\!\!\!\diagup}\cdot60\!\!\!\!\diagup=\dfrac{35\cdot6}{10}=\dfrac{210}{10}=21[/tex]

Answer:

The answer is 5

Step-by-step explanation:

get to the middle of the 5's and that's your answer =>=

Answer:

The answer is 5

Step-by-step explanation:

Answer:

11/25

Step-by-step explanation:

we can divide both top/bottom by 100, to get 11/25

:)