Question

A union of restaurant and foodservice workers would like to estimate the mean hourly wage, , of foodservice workers in the U.S. The union will choose a random sample of wages and then estimate using the mean of the sample. What is the minimum sample size needed in order for the union to be confident that its estimate is within of

Answer 1

Answer:  the minimum sample size needed = 145

Step-by-step explanation:

Formula for sample size:

$Sample \ size =(\dfrac{z^*\times standard\ deviation}{margin \ of \ error})^2$

, where z* = Critical z-value

Given: Standard deviation = 2.15

Margin of error = 0.35

Z* for 95% confidence = 1.96

Sample size = $(\frac{1.96\times2.15}{0.35})^2$

$=(12.04)^2\\\\=144.9616\approx145$

Hence, the minimum sample size needed = 145