Solve the problem. Round results to the nearest hundredth.
-A department store, on average, has daily sales of $28,372.72. The standard deviation of sales is $2000. On Tuesday, the store sold $34,885.21 worth of goods. Find Tuesday's z score. Was Tuesday an unusually good
Day?
A) 3.26, yes
B) 3.57, yes
C) 3.42, no
D) 2.61, no

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, the z-score is (34885.21 - 28372.72) / 2000 = 3.26. A z-score above 2 is typically considered unusual, so Tuesday was an unusually good day.

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