Question

Question3: Consider the following 11 independent measurements from a normal distribution:

Independent measurements
17	22	4	19	19	22	11	10	17	15	18

1) What is the standard error of the sample mean?
5.4921
1.7368
1.6559
9.0947

Tries 0/2

2) Calculate a 95% confidence interval for the population mean.
[12.8169,18.8194]
[12.1286,19.5078]
[13.2556,18.3808]
[5.9549,25.6814]

Thank you!

Answer 1

Solution:

1)

Standard error of the sample mean= s/√n

= 5.4921/√11 = 1.6559

2) 95% confidence interval for the population mean:

Sample size ,n =11

Sample Mean (average), X̄ =15.8182

Standard Deviation, s= 5.4921

Confidence Level= 95%

CI = X̄ ± t0.05× s/√n

( t0. 05  for (n-1) = 10 d. F is 2.228)

= 15.8182 ± 2.228× 5.4921/√11

= 15.8182 ± 3.6893

= [12.1286,19.5078]