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
<u>Answer:</u>
The Ranking Percentile is (B) 97.5%
<u>Explanation
:</u>
To find the percentile rank we need to find the z- score. After finding the z-score match this value with the corresponding value in z-score table.
Formula to find the z-score
Z-score=
Substituting the values in the above equation, we find
Z-score=
=2
So, the Z-score is +2
Now, the corresponding value of Z-score 2 in the table is 0.9772
or the percentile score is 97.72 ~ 97.5
.