In: Statistics and Probability
To lessen the financial burden of child care, a company is considering to reimburse its employees for child care expenses incurred while on the job. A random sample of 24 employees indicates the average weekly child care expense is $147.50 with a sample standard deviation of $46.75. Assuming these expenses are normally distributed, calculate the margin of error that will result when estimating the mean weekly child care expense for all employees at the company with a confidence level of 99%.
Do not round intermediate calculations. Round your final answer to 2 decimal places. Omit the "$" sign.
Margin of error =
dollars
solution
Given that,
= $147.50
s =$46.75
n = 24
Degrees of freedom = df = n - 1 =24 - 1 = 23
At 99% confidence level the t is ,
= 1 - 99% = 1 - 0.99 = 0.01
/ 2 = 0.01 / 2 = 0.005
t /2 df = t0.005,23 =2.807 ( using student t table)
Margin of error = E = t/2,df * (s /n)
= 2.807 * ( 46.75/ 24)
E=26.79
Margin of error = E =$26.79