Answer:
i think c
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
Answer:
about 22 square units
Step-by-step explanation:
sana makatulong
Answer: (36.7, 39.3)
Step-by-step explanation:
Confidence interval for population mean:
, where n= sample size,
= sample mean,
= population standard deviation,
= critical z value.
Given: n= 40 , 
Critical z-value for 90% confidence = 1.645
Then, required confidence interval:

Hence, a 90% Confidence Interval = (36.7, 39.3)