The z or t score to be used is (0.422,0.978)
How to find the critical value ?
Critical probability (p*) = 1 - (Alpha / 2), where Alpha is equal to 1 - (the confidence level / 100), is the unit statisticians use to determine the margin of error within a set of data in statistics.
The critical value for α = 0.13 is
The corresponding confidence interval is computed as shown below


CI = (0.422, 0.978)
0.422< mu1 - mu 2 < 0.978
To learn more about finding the critical value from the given link
brainly.com/question/14040224
#SPJ4
Answer:
About 3.11
Step-by-step explanation:
Add the numbers and divide the value by the number of values in the data set.
6 + 3 + 5 + 2 + 2 + 3 + 3 + 1 + 3 = 28
28/9 = 3.1111...
3.111... ≈ 3.11
Hope this helps.