Answer:
a) 90.1
b) $35.6
c) 3.0915 hours
Step-by-step explanation:
The z-score measures how many standard deviations a score X is above or below the mean.
It is given by the following formula:
In which is the mean and
is the standard deviaition.
In all three cases, we have to find X
a. Final exam scores: Allison’s z-score = 2.30, μ = 74, σ = 7.
b. Weekly grocery bill: James’ z-score = –1.45, μ = $53, σ = $12.
Mean and standard deviation in dollars, so the answer also in dollars.
c. Daily video game play time: Eric’s z-score = –0.79, μ = 4.00 hours, σ = 1.15 hours.
Mean and standard deviation in hours, answer in hours.
