Answer:the third one
Step-by-step explanation:
Answer:
18.0167≤x≤21.9833
Step-by-step explanation:
Given the following
sample size n = 10
standard deviation s = 3.2
Sample mean = 20
z-score at 95% = 1.96
Confidence Interval = x ± z×s/√n
Confidence Interval = 20 ± 1.96×3.2/√10
Confidence Interval = 20 ± (1.96×3.2/3.16)
Confidence Interval = 20 ± (1.96×1.0119)
Confidence Interval = 20 ± 1.9833
CI = {20-1.9833, 20+1.9833}
CI = {18.0167, 21.9833}
Hence the required confidence interval is 18.0167≤x≤21.9833
