Answer:
74.64%
Explanation:
Average sales (μ) = 50 hot dogs
Standard deviation (σ) = 7 hot dogs
In a normal distribution, the z-score for any given number of hot dogs sold, X, is determined by:
[tex]z=\frac{X-\mu}{\sigma}[/tex]
For X = 45 hot dogs:
[tex]z=\frac{45-50}{7}\\ z= -0.7143[/tex]
For X = 65 hot dogs:
[tex]z=\frac{65-50}{7}\\ z= 2.1429[/tex]
A z-score of -0.7143 falls in the 23.75th percentile of a normal distribution while a z-score of 2.1429 falls in the 98.39th percentile.
Therefore, the probability that he vendor will sell between 45 and 65 hot dogs is:
[tex]P(45 \leq X \leq 65) = 98.39-23.75\\P(45 \leq X \leq 65) = 74.64\%[/tex]