Question

a random sample of 150 students has a grade point average with a mean of 2.86. Assume the population standard deviation is 0.78. Constrict the confidence interval for the population mean ų, if c=0.98.

2.51, 3.53
2.31, 3.88
2.43, 3.79
2.71, 3.01

Answer 1

Mean () = 2.86
Sample size (n) = 150
Standard deviation (s) = 0.75
Confidence interval(in %) = 98
z @ 98.0% = 2.33
Since we know that

Required confidence interval =
Required confidence interval = (2.86-0.1427, 2.86+0.1427)
Required confidence interval = (2.7173, 3.0027)

Option D is correct
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