Answer:
Approximately 95% of the numbers of days will be between 26 and 58.
Step-by-step explanation:
We are given the following in the question:
Mean, μ = 42
Standard Deviation, σ = 8
We are given that the distribution of average number of days between a bill is a bell shaped distribution that is a normal distribution.
Empirical Formula:
Thus, by Empirical formula 95% of data lies within two standard deviation.
[tex]\mu \pm 2(\sigma) \\=42 \pm 2(8)\\=42 \pm 16\\=(26, 58)[/tex]
Thus, approximately 95% of the numbers of days will be between 26 and 58.