Given Information:
Average weekly amount spent on lunch = $44.31
Standard deviation = $3.08
Required Information:
Between what two values will approximately 68% of amounts be?
Solution:
Recall the Empirical Rule,
68% of the data will fall within 1 standard deviation from the mean.
95% of the data will fall within 2 standard deviations from the mean.
99.7 of the data will fall within 3 standard deviations from the mean.
Since we asked about 68% of the data so,
Lower limit = μ - (1)σ
Upper limit = μ + (1)σ
Where μ is the average weekly amount spent on lunch and σ is the standard deviation.
Lower limit = 44.31 - (1)3.08 = 44..31 - 3.08 = $41.23
Upper limit = 44.31 + (1)3.08 = 44..31 + 3.08 = $47.39
Therefore, approximately 68% of amounts will fall within $41.23 to $47.39