A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. They sampled 240 students and found a mean of 22.3 hours per week. Assuming a population standard deviation of 6 hours, what is the 99% level of confidence?
A) [21.80, 22.80]
B) [16.3, 28.3]
C) [21.30, 23.30]
D) [20.22, 22.0]

Question

Quizplus · Accepted Answer

The 99% confidence interval is calculated using the formula: mean ± (Z * (σ/√n)), where Z is the Z-score for 99% confidence (approximately 2.576), σ is the population standard deviation, and n is the sample size. Plugging in the values: 22.3 ± (2.576 * (6/√240)) gives the interval [21.30, 23.30].

A Group of Statistics Students Decided to Conduct a Survey