+61-413 786 465

[email protected]

## Statistics

problem1) Imagine that the sample of 400 rental units shows that (i) distribution of rents paid per month is not described by a normal distribution, (ii) the mean rent of the sample is \$755, and (iii) standard deviation of the sample is \$100.

a) Without seeing distribution, can you compute the probability that the rent of a randomly selected unit will be greater than \$800? If yes, compute the probability; if no, describe.
b) Without seeing the distribution, can you compute the probability that the mean rent of another sample of 400 units will be greater than \$800? If yes, find out the probability; if no, describe.
c) Why is the answer to (b) only an estimate? (What two numbers about whole population are you not sure of?)

problem2) Study done at the University of Maryland (cited in Weiss, Introductory Statistics, 7th ed, 2005) measured the body temperatures of 93 healthy humans. On the frequency- histogram below, I have superimposed a normal probability-density curve using the sample’s mean and standard deviation (98.12oF and  0.6468oF respectively)

a) Construct a 99% confidence interval for the mean temperature of all healthy humans.
b) Interpret your interval in words.
c) Draw this confidence interval in the space between the histogram and the box plot. Indicate both this sample’s mean, and the previously accepted value of 98.6oF.
d) You should now make a decision: the mean human-body- temperature is, or is not, 98.6oF. Which decision do you make? Briefly describe.

problem3) Imagine that you want to construct a 99% confidence interval for the mean body temperature for adult males. You want the interval’s margin of error to be to be 0.1 Fahrenheit degrees. You also happen to know that POPULATION’S standard deviation  is 0.63 Fahrenheit degrees. compute the size of the required sample.

problem4) Internal report issued by the marketing manager of a oil-change franchise claims that the mean number of miles between oil changes is for franchise customers is at least 3600 miles. One franchise owner suspects that the mean distance is actually less than 3600 miles. She collects a random sample of 10 customers, and determines the distance each had driven between oil changes. She finds the following results.

3655     3734    3700    1946    3208
3311    2789    3920    3555    3902

x‾= 3372  s=609

a) Construct a stem-and-leaf diagram.
b) Does your stem-and-leaf diagram  in (a) suggest that the distribution of distances is not normal? (For instance, is there any evidence that the distribution is skewed?)
c) Construct TWO 99% confidence intervals.
(i) Use the z-tables.
(ii) Use the t-tables.
d) Interpret your result in (ii) in words.
e) You now should decide: is the mean distance between oil changes 3600 miles, or not? describe your reasoning.
f) Which (if either) of the confidence intervals in (c) is appropriate? (Suggestion: look at your answer to (b).) describe briefly.

Statistics and Probability, Statistics

• Category:- Statistics and Probability
• Reference No.:- M9641

Have any Question?

## Related Questions in Statistics and Probability

### 151 153 152 146 148 152 15 152 15 154157 148 154 155 149

15.1 15.3 15.2 14.6 14.8 15.2 15 15.2 15 15.4 15.7 14.8 15.4 15.5 14.9 14.9 14.9 15.3 15.5 15.4 15.1 14.7 15.1 14.6 14.7 15.2 15.4 15.4 14.5 15.5 15.1 14.8 14.9 14.6 14.6 15.4 15 15.3 15.5 14.9 15.2 15.2 15 15.1 14.7 14. ...

### Out ofnbsp350nbspapplicants for a jobnbsp158nbspare female

Out of 350 applicants for a job, 158 are female and 66 are female and have a graduate degree. Step 1 of 2:  What is the probability that a randomly chosen applicant has a graduate degree, given that they are female? Expr ...

### Te number of accidents in a day in town a is given by x

The number of accidents in a day in town A is given by X , and the number of accidents in a day in town B is given by  Y . The joint probability function for  X   and  Y Y is  f ( x , y )=964 x ! y !   for  x =0,1,2,3 an ...

### A fair coin is flipped 100 times your friend proposes a bet

A fair coin is flipped 100 times. Your friend proposes a bet where if it lands on heads 49, 50, or 51 times, you win \$4, but if it lands on heads more than 51 times or less than 49 times, you lose \$1. Should you take the ...

### A certain diagnostic test is indicative of problems only if

A certain diagnostic test is indicative of problems only if a child scores in the lowest 10% of those taking the test (the 10th percentile). If the mean score is 150 with a standard deviation of 30, what would be the dia ...

### Carrie ds has 67 million shares of common stock outstanding

Carrie D's has 6.7 million shares of common stock outstanding, 3.7 million shares of preferred stock outstanding, and 27.00 thousand bonds. If the common shares are selling for \$29.80 per share, the preferred share are s ...

### Suppose you perform a multiple regression to predict crime

Suppose you perform a multiple regression to predict crime rate in a state and includes as indicators of predictions the homeownership rate divorce rate and the personal bankruptcy. Explain how to conduct a test of hypot ...

### Suppose you are a statistics consultant hired to study

Suppose you are a statistics consultant, hired to study whether a tax on alcohol has decreased average alcohol consumption in Australia. For a given sample of randomly selected individuals, you are able to obtain the dif ...

### An investment costs 60096 and offers a return of 10 percent

An investment costs \$60,096 and offers a return of 10 percent annually for ten years. What are the annual cash inflows anticipated from this investment? Use Appendix D to answer the question. Round your answer to the nea ...

### Question i dont understand how you would test if the data

Question: I don't understand how you would test if the data shows that there is a difference between some supplies if the testing level is at 1%? Can you show me the steps of how you would test if the data shows that the ...

• 13,132 Experts

## Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

### Why might a bank avoid the use of interest rate swaps even

Why might a bank avoid the use of interest rate swaps, even when the institution is exposed to significant interest rate

### Describe the difference between zero coupon bonds and

Describe the difference between zero coupon bonds and coupon bonds. Under what conditions will a coupon bond sell at a p

### Compute the present value of an annuity of 880 per year

Compute the present value of an annuity of \$ 880 per year for 16 years, given a discount rate of 6 percent per annum. As

### Compute the present value of an 1150 payment made in ten

Compute the present value of an \$1,150 payment made in ten years when the discount rate is 12 percent. (Do not round int

### Compute the present value of an annuity of 699 per year

Compute the present value of an annuity of \$ 699 per year for 19 years, given a discount rate of 6 percent per annum. As