Find the standard deviation of the data summarized in the given frequency distribution.
-A department store, on average, has daily sales of $29,112.90. The standard deviation of sales is $1500. On Tuesday, the store sold $35,669.13 worth of goods. Find Tuesday's z score. Was Tuesday an unusually good day?
A)4.59, no
B)3.50, no
C)4.37, yes
D)4.68, yes

Question

Quizplus · Accepted Answer

The z score is calculated as (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation. For Tuesday, z = ($35,669.13 - $29,112.90) / $1500 = 4.37. A z score above 2 or below -2 is considered unusual, so Tuesday was unusually good.

Find the Standard Deviation of the Data Summarized in the Given