3.3) A small market orders copies of a certain magazine for its magazine rack each week. Let X = demand for the magazine, with the following pmf.

Suppose the store owner actually pays $2.00 for each copy of the magazine and the price to customers is $4.00. If magazines left at the end of the week have no salvage value, is it better to order three or four copies of the magazine? [Hint: For both three and four copies ordered, express net revenue as a function of demand X, and then compute the expected revenue.]

*What is the expected profit if three magazines are ordered? (Round your answer to two decimal places.)

*What is the expected profit if four magazines are ordered? (Round your answer to two decimal places.)

*How many magazines should the store owner order?

-3 magazines

-4 magazines

Based on historical data, your manager believes that 33% of the company's orders come from first-time customers. A random sample of 102 orders will be used to estimate the proportion of first-time-customers. What is the probability that the sample proportion is less than 0.27? Note: You should carefully round any z-values you calculate to 4 decimal places.

Answer =

(Enter your answer as a number accurate to 4 decimal places.)

Let x be a random variable that represents the level of glucose in the blood (milligrams per deciliter of blood) after a 12 hour fast. Assume that for people under 50 years old, x has a distribution that is approximately normal, with mean μ = 65 and estimated standard deviation σ = 31. A test result x < 40 is an indication of severe excess insulin, and medication is usually prescribed.

(a) What is the probability that, on a single test, x < 40? (Round your answer to four decimal places.)


(b) Suppose a doctor uses the average x for two tests taken about a week apart. What can we say about the probability distribution of x? Hint: See Theorem 6.1.

The probability distribution of x is not normal.The probability distribution of x is approximately normal with μ_x = 65 and σ_x = 21.92.    The probability distribution of x is approximately normal with μ_x = 65 and σ_x = 31.The probability distribution of x is approximately normal with μ_x = 65 and σ_x = 15.50.

What is the probability that x < 40? (Round your answer to four decimal places.)


(c) Repeat part (b) for n = 3 tests taken a week apart. (Round your answer to four decimal places.)


(d) Repeat part (b) for n = 5 tests taken a week apart. (Round your answer to four decimal places.)


(e) Compare your answers to parts (a), (b), (c), and (d). Did the probabilities decrease as n increased?

YesNo    

Explain what this might imply if you were a doctor or a nurse.

The more tests a patient completes, the weaker is the evidence for excess insulin.The more tests a patient completes, the stronger is the evidence for excess insulin.    The more tests a patient completes, the weaker is the evidence for lack of insulin.The more tests a patient completes, the stronger is the evidence for lack of insulin.

Suppose that finishing times of runners in a local 10K race follow an approximate normal distribution with mean 61 minutes and standard deviation 9 minutes.

(a) Melissa finished the race in 52 minutes. How many standard deviations below average is Melissa's time?

(b) What is the probability that a randomly selected runner completed the race in between 43 and 52 minutes?

(c) Jennifer's finishing time was 79 minutes. What percentage of runners had faster times than Jennifer?

(d) The fastest 16% of runners finished the race in less than how many minutes?

If n = 240 and ˆ p (p-hat) = 0.7, construct a 99% confidence interval. Give your answers to three decimals

< p <

An advertising executive wants to estimate the mean weekly amount of time consumers spend watching traditional television daily. Based on previous​ studies, the standard deviation is assumed to be 21 minutes. The executive wants to​ estimate, with​ 99% confidence, the mean weekly amount of time to within ± 6 minutes.

a. What sample size is​ needed?

b. If​ 95% confidence is​ desired, how many consumers need to be​ selected?

A sales region has been divided into five territories, each of which was believed to have equal sales potential. The actual sales volume for several sampled days is logged in DATA. At x = 0.05, do the territories have equal sales volume?

A. HO: Territories have equal sales volume is not rejected with pvalue 0.074. The counts are consistent with the model of equal proportions.

B. HO: Territories have equal sales volume is rejected with pvalue 0.012. The counts are not consistent with the model of equal proportions. Territories have unequal sales volume.

C. HO: Territories have equal sales volume is not rejected with pvalue 0.334. The counts are consistent with the model of equal proportions.

D. none of the answers are correct

E. HO: Territories have equal sales volume is rejected with pvalue 0.041. The counts are not consistent with the model of equal proportions. Territories have unequal sales volume

36. Continuing Problem 18, suppose that the antique collector believes that the rate of increase of the auction price with the age of the item will be driven upward by a large number of bidders. How would you revise the multiple regression equation developed previously to model this feature of the problem? a. Estimate your revised equation using the data in the file P10_18.xlsx. b. Interpret each of the estimated coefficients in your revised model. c. Does this revised model fit the given data better than the original multiple regression model? Explain why or why not.

A customer service phone line claims that the wait times before a call is answered by a service representative is less than 3.3 minutes. In a random sample of 62 calls, the average wait time before a representative answers is 3.24 minutes. The population standard deviation is assumed to be 0.40 minutes. Can the claim be supported at α=0.08?

The distribution of the number of viewers for the American Idol television show follows a normal distribution with a mean of 29 million with a standard deviation of 6 million.

What is the probability next week's show will:

1. Have between 32 and 41 million viewers? (Round your z-score computation to 2 decimal places and final answer to 4 decimal places.)

2. Have at least 24 million viewers? (Round your z-score computation to 2 decimal places and final answer to 4 decimal places.)

3. Exceed 46 million viewers? (Round your z-score computation to 2 decimal places and final answer to 4 decimal places.)

To find out whether a new serum will arrest leukemia, 10 mice, all with an advanced stage of the disease, are selected. Five mice receive the treatment and 5 do not. Survival times, in years, from the time the experiment commenced are as follows:

Treatment:            2.1         5.3       1.4       4.6       0.9

No Treatment:      1.9         0.5       2.8       3.1       2.7

Using the above data , the true average lifetime of mice with no treatment is more than 3 months smaller than it is for the mice with treatment? Assume the two populations to be normally distributed with equal variability.

To find out whether a new serum will arrest leukemia, 10 mice, all with an advanced stage of the disease, are selected. Five mice receive the treatment and 5 do not. Survival times, in years, from the time the experiment commenced are as follows:

Treatment:            2.1         5.3       1.4       4.6       0.9

No Treatment:      1.9         0.5       2.8       3.1       2.7

a) Can the serum be said to be effective? Assume the two populations to be normally distributed.

b) Verify your work in part a) with an appropriate confidence interval. (Don’t forget to state the appropriate level of confidence)

I need new and unique answers, please. (Use your own words, don't copy and paste), Please Use your keyboard (Don't use handwriting) Thank you..

Q1. What is the difference between simple linear regression and multiple linear regression?

Q2. What is the difference between R, R² and adjusted R² in multiple linear regression.

You may need to use the appropriate appendix table or technology to answer this question.

Older people often have a hard time finding work. A research group reported on the number of weeks it takes a worker aged 55 plus to find a job. The data on number of weeks spent searching for a job is given in the table below.

(a)

Provide a point estimate of the population mean number of weeks it takes a worker aged 55 plus to find a job.

weeks

(b)

At 95% confidence, what is the margin of error? (Round your answer to four decimal places.)

weeks

(c)

What is the 95% confidence interval estimate of the mean? (Round your answers to two decimal places.)

weeks to  weeks

(d)

Discuss the degree of skewness found in the sample data. What suggestion would you make for a repeat of this study?

A histogram of the data shows the distribution is perfectly symmetric. One might suggest collecting a smaller sample, at most 15, in the future.A histogram of the data shows some evidence that the distribution may be skewed to the right. One might suggest collecting a larger sample, at least 50, in the future.     A histogram of the data shows some evidence that the distribution may be skewed to the right. One might suggest collecting a smaller sample, at most 15, in the future.A histogram of the data shows the distribution is perfectly symmetric. One might suggest collecting a larger sample, at least 50, in the future.