A decade-old study found that the proportion, p, of high school seniors who believed that "getting rich" was an important personal goal was 70%. A researcher decides to test whether or not that percentage still stands. He finds that, among the 205 high school seniors in his random sample, 159 believe that "getting rich" is an important goal. Can he conclude, at the 0.05 level of significance, that the proportion has indeed changed? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places.      Find the value of the test statistic and round to 3 or more decimal places. (I have posted a picture of an example problem and the equation to use, with the correct answer as every expert I have asked thus far has gotten this problem wrong.) A. Find the value of the test statistic. (Round to three or more decimal places.) B. Find the p-value. (Round to three or more decimal places.) C. Can we conclude that the proportion of high school seniors who believe that "getting rich" is an important goal has changed?

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
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Chapter1: Starting With Matlab
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A decade-old study found that the proportion, p, of high school seniors who believed that "getting rich" was an important personal goal was 70%. A researcher decides to test whether or not that percentage still stands. He finds that, among the 205 high school seniors in his random sample, 159 believe that "getting rich" is an important goal. Can he conclude, at the 0.05 level of significance, that the proportion has indeed changed?
Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places.     

Find the value of the test statistic and round to 3 or more decimal places. (I have posted a picture of an example problem and the equation to use, with the correct answer as every expert I have asked thus far has gotten this problem wrong.)

A. Find the value of the test statistic. (Round to three or more decimal places.)

B. Find the p-value. (Round to three or more decimal places.)

C. Can we conclude that the proportion of high school seniors who believe that "getting rich" is an important goal has changed?

 

 

(c) Finding the value of the test statistic
The value of this test statistic is the z-value corresponding to the sample proportion under the assumption that His true. Here is i
P-P
p(1-p)
n
36
43
0.80
0.80(1-0.80)
215
1.364
Transcribed Image Text:(c) Finding the value of the test statistic The value of this test statistic is the z-value corresponding to the sample proportion under the assumption that His true. Here is i P-P p(1-p) n 36 43 0.80 0.80(1-0.80) 215 1.364
A marriage counselor has traditionally seen that the proportion p of all married couples for whom her communication program can prevent divorce is 80%.
After making some recent changes, the marriage counselor now claims that her program can prevent divorce in more than 80% of married couples. In a
random sample of 215 married couples who completed her program, 180 of them stayed together. Based on this sample, is there enough evidence to support
the marriage counselor's claim at the 0.05 level of significance?
Perform a one-tailed test. Then complete the parts below.
Carry your intermediate computations to three or more decimal places. (If necessary, consult a list of formulas.)
Transcribed Image Text:A marriage counselor has traditionally seen that the proportion p of all married couples for whom her communication program can prevent divorce is 80%. After making some recent changes, the marriage counselor now claims that her program can prevent divorce in more than 80% of married couples. In a random sample of 215 married couples who completed her program, 180 of them stayed together. Based on this sample, is there enough evidence to support the marriage counselor's claim at the 0.05 level of significance? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places. (If necessary, consult a list of formulas.)
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