68-40=28
28/4=7
therefore, 7 is your answer
(Hope it helps my friend ^_^)
Answer: 40%
Step-by-step explanation:
The corresponding z score for speed of 62 mph, 47 mph, and 56 mph is 1.5, -2.25 and 0 respectively.
<h3>
Z score</h3>
Z score is used to determine by how many standard deviations the raw score is above or below the mean. It is given by:

Where x is raw score, μ is mean, σ is standard deviation
Given that:
σ = 4, μ = 56, hence
for x = 62:

for x = 47:

for x = 56:

The corresponding z score for speed of 62 mph, 47 mph, and 56 mph is 1.5, -2.25 and 0 respectively.
Find out more on Z score at: brainly.com/question/25638875