Respuesta :
Using the normal distribution, it is found that the percentage of their weekly sales over P4,000 is given by:
C. 5.48%
Normal Probability Distribution
In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
- It measures how many standard deviations the measure is from the mean.
- After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.
In this problem, the mean and the standard deviation are, respectively, of [tex]\mu = 3200, \sigma = 500[/tex].
The proportion of their weekly sales over P4,000 is 1 subtracted by the p-value of Z when X = 4000, hence:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{4000 - 3200}{500}[/tex]
[tex]Z = 1.6[/tex]
[tex]Z = 1.6[/tex] has a p-value of 0.9452.
1 - 0.9452 = 0.0548 = 5.48%.
Hence option C is correct.
More can be learned about the normal distribution at https://brainly.com/question/24663213
