Answer:
Z-score = 3.26
Explanation:
The Z-score formula to employ is given as follows:
Z = (X - U) ÷ SD ..................................................... (1)
Where,
Z = the z-score = ?
X = Tuesday's sales = $34,885.21
U = Average or mean of daily sales = $28,372.72
SD = Standard deviation of sales = $2,000
Substituting each variable into equation (1), we can calculate the z-score as follows:
Z = ($34,885.21 - $28,372.72) ÷ $2,000
= $6,512.49 - $2,000
= 3.26
The Z-score of 3.26 implies that the Tuesday's sales is 3.26 standard deviation above the mean. Given the empirical rules of 95%, the Tuesday's sales is not significantly higher than 3 standard deviations above the mean.
Therefore, the sales on Tuesday were good.
