The mean number of English courses taken in a two–year time period by male and female college students is believed
to be about the same. An experiment is conducted and data are collected from 29 males and 16 females. The males took an
average of three English courses with a standard deviation of 0.8. The females took an average of four English courses with
a standard deviation of 1.0. Are the means statistically the same?

Short Answer

Expert verified

We reject hypothesis H0and conclude at 5% significance level, and provide sufficient evidence to conclude that the mean number of college English course that males and females takes is different.

Step by step solution

01

Given Information

Find the male and female of English course

02

Part (a) Step 2: Explanation

Given the table with data:

AssumeX1-X2 represent that the difference between the mean of English course taken by males and females

Test these hypothesis:

H0:μ1=μ2H1:μ1μ2

To perform the test, we need to distribute the student.

First, calculate the standard error:

SE=s21n1+s22n2=0.8229+1216=0.084569=0.290807

03

Part (b) Step 3: Calculation

Test statistic

t=X1-X2SE=3-4SE=-3.438707

Now we have to find the number of degree of freedom of our test statistic and for that, we are using the formula

df=SEs41n21(n1-1)+s42n21(n2-1)=25.7436

04

Part (c) Step 4: Graph

We get the p=0.002

If we take α=0.05, then p- value is less than 0.005, thus we reject the hypothesis H0and conclude that at 5%significance level, and there is a sufficient evidence to conclude that the mean number of college English course that male and female takes is different

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Most popular questions from this chapter

Use the following information to answer the next 12 exercises: The U.S. Center for Disease Control reports that the mean life expectancy was 47.6 years for whites born in 1900 and 33.0 years for nonwhites. Suppose that you randomly survey death records for people born in 1900 in a certain county. Of the 124 whites, the mean life span was 45.3 years with a standard deviation of 12.7 years. Of the 82 nonwhites, the mean life span was 34.1 years with a standard deviation of 15.6 years. Conduct a hypothesis test to see if the mean life spans in the county were the same for whites and nonwhites.

Calculate the test statistic and p-value.

Use the following information to answer the next five exercises. The mean speeds of fastball pitches from two different baseball pitchers are to be compared. A sample of 14 fastball pitches is measured from each pitcher. The populations have normal distributions. Table 10.18 shows the result. Scouters believe that Rodriguez pitches a speedier fastball.

At the 1 % significance level, what is your conclusion?

Use the following information to answer the next five exercises. The mean speeds of fastball pitches from two different baseball pitchers are to be compared. A sample of 14 fastball pitches is measured from each pitcher. The populations have normal distributions. Table 10.18 shows the result. Scouters believe that Rodriguez pitches a speedier fastball.

What is the random variable?

Use the following information to answer the next 15 exercises: Indicate if the hypothesis test is for

a. independent group means, population standard deviations, and/or variances known

b. independent group means, population standard deviations, and/or variances unknown

c. matched or paired samples

d. single mean

e. two proportions

f. single proportion

A sample of 12 in-state graduate school programs at school A has a mean tuition of \(64,000 with a standard deviation of \)8,000. At school B, a sample of 16 in-state graduate programs has a mean of \(80,000 with a standard deviation of \)6,000. On average, are the mean tuitions different?

Weighted alpha is a measure of risk-adjusted performance of stocks over a period of a year. A high positive weighted alpha signifies a stock whose price has risen while a small positive weighted alpha indicates an unchanged stock price during the time period. Weighted alpha is used to identify companies with strong upward or downward trends. The weighted alpha for the top 30 stocks of banks in the northeast and in the west as identified by Nasdaq on May 24,2013 are listed in Table 10.6 and Table10.7, respectively

Is there a difference in the weighted alpha of the top 30 stocks of banks in the northeast and in the west? Test at a 5% significance level. Answer the following questions:

a. Is this a test of two means or two proportions?

b. Are the population standard deviations known or unknown?

c. Which distribution do you use to perform the test?

d. What is the random variable?

e. What are the null and alternative hypotheses? Write the null and alternative hypotheses in words and in symbols.

f. Is this test right, left, or two tailed?

g. What is the p-value?

h. Do you reject or not reject the null hypothesis?

i. At the ___ level of significance, from the sample data, there ______ (is/is not) sufficient evidence to conclude that ______.

j. Calculate Cohen’s d and interpret it

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