Thirty randomly selected students took the calculus final.If the sample mean was 95 and the standard deviation was 6.4, construct a 99% confidence interval for the mean score of all
Students.
A)(92.12, 97.88)
B)(91.78, 98.22)
C)(93.01, 98.21)
D)(93.01, 96.99)
E)(91.79, 98.21)

Question

Quizplus · Accepted Answer

To construct a 99% confidence interval for the mean, we use the formula: mean ± (z * (standard deviation/√n)). For a 99% confidence level, the z-value is approximately 2.576. Plugging in the values: 95 ± (2.576 * (6.4/√30)) gives the interval (91.78, 98.22).

Thirty Randomly Selected Students Took the Calculus Final