Question

Students who have completed a speed reading course have reading speeds that are normally distributed with a mean of 950 words per minute and a standard deviation equal to 220 words per minute. Based on this information, what is the probability of a student reading at more than 1400 words per minute after finishing the course

Answer 1

Answer:

0.020405

Step-by-step explanation:

We solve this question, using z score formula.

z-score formula =

z = (x-μ)/σ,

where x is the raw score

μ is the population mean

σ is the population standard deviation.

From the above question:

x = 1400, μ = 950, σ = 220

z = 1400 - 950/220

z = 2.04545

Determining the probability from Z-Table:

P(z = 2.04545) = P(x<1400) = 0.97959

P(x>1400) = 1 - P(x<1400)

= 1 - 0.97959

= 0.020405

Therefore, the probability of a student reading at more than 1400 words per minute after finishing the course is 0.020405