MATLAB: An Introduction with Applications
6th Edition
ISBN: 9781119256830
Author: Amos Gilat
Publisher: John Wiley & Sons Inc
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number with "1" as the leading digit is about 0.303. Now suppose you are the auditor for a very large corporation. The revenue file contains millions of numbers in a large computer data bank. You draw a random sample of n = 225 numbers from this file and r = 86 have a first nonzero digit of 1. Let p represent the population proportion of all numbers in the computer file that have a leading digit of 1.
Test the claim that p is more than 0.303. Use ? = 0.10.
(a) What is the level of significance?
State the null hypothesis
(b) What sampling distribution will you use?
and nq
What is the value of the sample test statistic? (Round your answer to two decimal places.)
(c) Find the P-value of the test statistic. (Round your answer to four decimal places.)
Sketch the sampling distribution and show the area corresponding to the P-value.
(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level ??
(e) Interpret your conclusion in the context of the application.
State the null hypothesis
H0
and the alternate hypothesis
H1
.H0
: p H1
: p (b) What sampling distribution will you use?
The Student's tThe standard normal
since np and nq
What is the value of the sample test statistic? (Round your answer to two decimal places.)
(c) Find the P-value of the test statistic. (Round your answer to four decimal places.)
Sketch the sampling distribution and show the area corresponding to the P-value.
(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level ??
At the ? = 0.10 level, we reject the null hypothesis and conclude the data are statistically significant.At the ? = 0.10 level, we reject the null hypothesis and conclude the data are not statistically significant. At the ? = 0.10 level, we fail to reject the null hypothesis and conclude the data are statistically significant.At the ? = 0.10 level, we fail to reject the null hypothesis and conclude the data are not statistically significant.
(e) Interpret your conclusion in the context of the application.
There is sufficient evidence at the 0.10 level to conclude that the true proportion of numbers with a leading 1 in the revenue file is greater than 0.303.There is insufficient evidence at the 0.10 level to conclude that the true proportion of numbers with a leading 1 in the revenue file is greater than 0.303.
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