Question

An industrial/organizational psychologist wants to improve worker productivity for a client firm, but first she needs to gain a better understanding of the life of the typical white-collar professional. Fortunately, she has access to the 2008 Workplace Productivity Survey, commissioned by LexisNexis and prepared by WorldOne Research, which surveyed a sample of 650 white-collar professionals (250 legal professionals and 400 other professionals). One of the survey questions was, "How many hours do you work at your job on a typical workday?" For the subsample of legal professionals (n = 250), the mean response was M = 9.0 hours, with a sample standard deviation of s = 10.4 hours.

Answer 1

Answer:

a) Standard Error = 0.6578

b) 99% confidence interval = (7.303, 10.697)

c) A population mean of 8.5 hours would not surprise the psychologist as this is within the confidence interval.

Step-by-step explanation:

a) Standard error = Standard deviation/√n

n = sample size = 250

Standard deviation = 10.4

Standard error = (10.4/√250)

Standard error = 0.6578

b) 99% confidence interval

Confidence interval = (Sample mean) ± (Margin of error)

Sample mean = 9 hours

Margin of Error = (critical value) × (standard error or standard deviation of the distribution of sample means)

Critical value for a 99% confidence interval = 2.58 (from the z-tables)

Standard error or standard deviation of the distribution of sample means = 0.6578

margin of error = 2.58 × 0.6578 = 1.697

Confidence interval = 9 ± 1.697

Lower limit of the confidence interval = 9 - 1.697 = 7.303 hours

Upper limit of the confidence interval = 9 + 1.697 = 10.697 hours

99% confidence interval = (7.303, 10.697)

c) A population mean of 8.5 hours would not surprise the psychologist as this is within the confidence interval.

Hope this Helps!!!