A company offering online speed reading courses claims that students who take their courses show a 5 times (500%) increase in the number of words they can read in a minute without losing comprehension. A random sample of 100 students yielded an average increase of 415% with a standard deviation of 220%. Calculate a 95% confidence interval for the average increase in number of words students can read in a minute without losing comprehension. Choose the closest answer.

C.I = (371.88  , 458.12)

Step-by-step explanation:

Given that:

sample size n = 100

sample mean 415

standard deviation = 220

The objective is to calculate the  95% confidence interval for the average increase in number of words students who can read in a minute without losing comprehension.

At 95% confidence interval; level of significance ∝ = 1 - 0.95

level of significance ∝ = 0.05

The critical value at is 1.96

C.I =

C.I =

C.I =

C.I =

C.I =

C.I =

C.I = (371.88  , 458.12)

10

step-by-step explanation:

3: 2

step-by-step explanation:

shorter piece is 2: 3, so just reverse it, and you get 3: 2