A study was done to test the claim that the average waiting time in ER is 20 min.
Sample of N=100 patients were checked, and the average waiting time was found as x¯ = 23 min.
Distribution is normal, and population standard deviation is σ = 15 min.
Complete the Hypothesis Testing at the significance level 1% and make the decision if the sample data support the claim or the average waiting time in this ER is different (this is Two-Tails test).