Question

Assignment 6
1. The true proportion of accounts receivable with some kind of error is 8 percent for Moby Group. If an auditor randomly samples 100 accounts receivable,
• a) is it acceptable to use the normal approximation to estimate the probability that fewer than two will contain errors? Explain your reasoning.
• b) what is the mean and standard deviation of errors?
• c) assume the auditor takes a sample of 150, what is the probability that less than 5 will contain errors?
2. The weights of sheep available for sale for during Eid Qurban is normally distributed with a mean weight of 45kgs and standard deviation of 5kgs.
• what is the probability that you buy a sheep and its weight is more than 50kgs?
• If you want the weight of your sheep to be in the 80th percentile, what should be the weight of the sheep that you should buy?
3. A car service shop services a vehicle with an average of 15 minutes and standard deviation of 2 minutes. Assuming the length of time is normally distributed,
• a) what is the probability that you will get your car serviced in more than 18 minutes?
• b) what is the probability that you will get your car serviced in less than 14 minutes?
• c) how long it will take for the middle 70% of customers to get their car serviced?
4. The time required to complete a marathon run is normally distributed with a mean of 360 minutes and a standard deviation of 15 minutes.
• a) what is the maximum number of minutes that the fastest 15% of runners will take to finish the race?
• b) what is the least number of minutes that the slowest 15% will take to finish the race?
5. The standard deviation of a normal random variable X is $50 . Given that P(X ≤ $40) = .25, what is the mean of the distribution is equal to?


6. City Medical is concerned about rising lab test costs and would like to know what proportion of the negative lab tests for COVID19 are actually proven correct through subsequent blood test. City Medical demands a sample large enough to ensure an error of ±0.5% with 95% confidence. What should be the sample size?

Answer 1

Answer:

sory mere ko eska answer nhi pta very very sory