Question
A random sample of state gasoline taxes is shown for 12 states. Use the data to estimate the true population mean gasoline tax with 90% confidence. Does your interval contain the national average of 0.21? assume normal distribution.
Answers
PsyDAG
Lacking sample data.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (±.05) to get the Z score.
90% = mean ± 1.645 SEm
SEm = SD/√n
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (±.05) to get the Z score.
90% = mean ± 1.645 SEm
SEm = SD/√n