Answer:
The proportion of hours will be the number of purchases at the online store exceed 1,400
P(z>1) = 0.1587
Step-by-step explanation:
Step (i):-
Given mean of the Population (μ) = 1200
Standard deviation of the population (σ) = 200
let X be the random variable in normal distribution
Given x = 1400
Step(ii) :-
The proportion of hours will be the number of purchases at the online store exceed 1,400
[tex]Z = \frac{1400-1200}{200} = 1[/tex]
P(z>1) = 0.5 - A(1)
= 0.5 - 0.3413
= 0.1587
The percentage of hours will be the number of purchases at the online store exceed 1,400 is 15.87%
Answer:
Answer C
Step-by-step explanation:
By the empirical rule, 68% of the number of purchases in an hour will be between 1,000 and 1,400, so 100%−68%=32% of the number of purchases in an hour will fall outside of the interval. Since the normal distribution is symmetric around the mean, half of 32%, which is 16%, of the number of purchases in an hour will exceed 1,400.
