In: Statistics and Probability
The following summary statistics were derived from a simple random sample:
Mean=63.7
Standard deviation=14.1
n=51
Compute a 99% confidence interval for the population mean. Report the upper limit for your answer.
Solution :
Given that,
Point estimate = sample mean = = 63.7
sample standard deviation = s = 14.1
sample size = n = 51
Degrees of freedom = df = n - 1 = 51 - 1 = 50
At 99% confidence level the t is ,
= 1 - 99% = 1 - 0.99 = 0.01
t,df = t0.01,50 = 2.403
Margin of error = E = t,df * (s /n)
= 2.403 * (14.1 / 51)
Margin of error = E = 4.7
At 99% upper confidance level is
+ E
63.7 + 4.7
68.4
The upper limit : 68.4