Question

Researchers doing a study comparing time spent on social media and time spent on studying randomly sampled 200 students at a major university. They found that students in the sample spent an average of 2.3 hours per day on social media and an average of 1.8 hours per day on studying. If all the students at the university in fact spent 2.2 hours per day on studying, with a standard deviation of 2 hours, and we find the probability of observing a sample mean of 1.8 hours studying has an extremely low probability, we say that observed time is:

Answer 1

Consider the following calculations

Explanation:

Given that,

mean = u = 2.2

standard deviation = sigma = 2

n = 200

The sampling distribution of mean and standard deviation is ,

Ux = 2.2 and

U x = sigma / n = 2 / \sqrt 200 = 0.141

N(2.2 , 0.141)