stat hw!!

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can anyone help me with this?

Problem 1:

Paris Hilton decided to go to college and study Statistics. Her first project deals with statistical analysis of sampling distributions. She goes to a local Hollywood elite bar and learns that an average drink costs μ = $8 with a standard deviation of σ = 2.1. She sees that there are 50 people in the bar. Suppose each one buys one drink. Being a serious stats student, Paris feels uncomfortable asking each of these 50 people how much they have paid for their drink. Help Paris answer the following questions:
a) Describe the distribution of the average price these 50 people are paying for a drink.
b) What is the probability that the average price these 50 people are paying for a drink ranges between $8 and $10?
c) What is the probability that, if each one of these 50 people buys one drink, this Hollywood elite bar would make altogether over $500 (assume there are no tips)?


Problem 2:

You would like to know for how many years a typical driver in the Mexico city has been driving. Suppose that historically the mean driving time is 8 years and the standard deviation is 0.6 years. You travel to Mexico and plan to ask 35 random people on the streets about how many years they have been driving.
a) Can you say that the distribution of the average driving time for these 35 people is Normal? Explain. Describe the distribution of the average driving time.
b) What is the probability that the average driving time for these 35 people would be no more than 7.9 years?
c) What is the probability that the average driving time for these 35 people would be within half a year from the population mean of 8 years?




Problem 3:

Grocery store receipts show that customer purchases have a skewed distribution with a mean of $32 and a standard deviation of $20. Suppose the store had 312 customers today.

a) Estimate the probability that the store’s total revenues were at least $10,000.
b) If in a typical day the store serves 300 customers, how much does the store take in on the worst 10% of such days? (Hint: find the amount for the store’s revenues such that the probability of going below that is 10%.)



Problem 4:
Read the article from CNN.com titled “Poll: 75 percent disapprove of Congress’ performance” and answer the following questions:

a) Explain clearly how the approval/disapproval rating figures were obtained in the survey. (Hint: do not guess. This information is actually given in the article.)

Your stats professor asks you to double-check the figures that appear in the article and gives you 1 hour time to go and ask 100 people on the street whether or not they approve or disapprove of the way Congress is handling its job.
You feel there is not enough time to survey 100 people but want to be able to give her a reasonable answer. Answer the following questions:

b) If the figures that appear in the article represent population figures, then what would be your estimate of the probability that of these 100 people between 70 and 80 would say they disapprove of the way Congress is handling its job? Make sure you give a reasonable explanation to your stats professor about how you obtained your numbers.
c) Refer to part b) of this problem. Similarly, if the figures that appear in the article represent population figures, then of these 100 people, what is the probability that more than 30% would say they approve of the way Congress is handling its job? Make sure you give a reasonable explanation to your stats professor about how you obtained your numbers.