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the US census bureau reports that the average number of employees in a small bus

ID: 3378589 • Letter: T

Question


the US census bureau reports that the average number of employees in a small business is 16.1. suppose a sample of 49 small businesses showed a mean of 15 employees with a standard deviation of 25. test whether the population mean number of employees is different from 16.1 using the confidence interval. (significance level a=0.01)
the US census bureau reports that the average number of employees in a small business is 16.1. suppose a sample of 49 small businesses showed a mean of 15 employees with a standard deviation of 25. test whether the population mean number of employees is different from 16.1 using the confidence interval. (significance level a=0.01)
the US census bureau reports that the average number of employees in a small business is 16.1. suppose a sample of 49 small businesses showed a mean of 15 employees with a standard deviation of 25. test whether the population mean number of employees is different from 16.1 using the confidence interval. (significance level a=0.01)

Explanation / Answer

Mean = 16.1

n=49

Sample Mean = 15

Sample SD = 25

Confidence level = 100(1) % = 100(10.01) % = 99%

Therefore, z value for 99% = 2.576

Confidence Interval Approach:

Margin of Error = (z*SD)/sqrt(n)

= (2.576 * 25)/sqrt(49)

= 9.2

Confidence Interval:

( Mean - Margin of Error , Mean + Margin of error)

= (15 - 9.2 , 15 + 9.2 )

= ( 5.8 , 24.2 )

True Mean 16.1 lies in this interval.

The confidence interval includes all null hypothesis values for the population mean that would be accepted by an hypothesis test at the 1 % significance level.