Answer: Mean = 5.25
Variance = 1.3125
Standard deviation = 1.456
Step-by-step explanation:
The mean and variance of a binomial distribution with parameters n (number of trials) and p ( the probability of getting success in each trial) is given by :-

Given : The total number of enter a clothing store : n=7
The probability of a customer making a purchase= 0.75
Now,

Answer:
it is b
Step-by-step explanation:
Answer: It’s not 17.5 I can tell you that:(( just got it wrong
Step-by-step explanation:
Answer:
He must work 52 days to pay for a single ticket.
Step-by-step explanation:
This question can be solved using proportions.
Per hour:
Joel earns $7.25 per hour, 20% of which is deducted for taxes. So without taxes, in each hour, he earns 100%-20% of 80% of this, so 0.8*7.25 = $5.8.
Per day:
He works 9 a.m. to 5 p.m. each day, so 8 hours a day.
For each hour, he earns $5.8.
So in a day, he makes 8*5.8 = $46.4
How many days he must work:
The ticket costs $2400.
He makes $46.4 a day.
So, to buy a ticket, he needs to work:
2400/46.4 = 51.7 days
Rounding up
He must work 52 days to pay for a single ticket.