During the last week of the semester, students at a certain college spend on the average 4.2 hours using the school’s computer terminals with a standard deviation of 1.8 hours. For a random sample of 36 students at that college, find the probabilities that the average time spent using the computer terminals during the last week of the semester is a) At least 4.8 hours (Draw the bell curve) b)

Respuesta :

fichoh

Answer:

0.97725

Step-by-step explanation:

Given :

Population mean, μ = 4.2

Population standard deviation, σ = 1.8

Sample size, n = 36

Obtain the Zscore of x = 4.8

Zscore = (x - μ) ÷ (σ / √n)

Zscore = (4.8 - 4.2) ÷ (1.8 / √36)

Zscore = 0.6 ÷ 0.3

Z = 2

Hence,

P(Z ≤ 2)

Using the Z probability calculator :

P(Z ≤ 2) = 0.97725