A concrete service owns 3 mixer trucks to deliver concrete to work sites in a local area. For each order, a truck is loaded and weighed with mix at the single station for the order. Then the truck makes the delivery and returns for the next load. Assume that there is always an order for each truck. The delivery times are 15 minutes plus an exponential amount with mean 30 minutes and load/weigh times are 8 minutes. This is a variation on the single server queue with a fixed population of trucks. Trucks are served at the loader and return to it as arrivals following their delivery. Simulate this system by hand for 3 hours simulated time and report on the number of deliveries completed. The trucks begin empty, ready to be loaded.

1. A $1 scratch off lotto ticket will be a winner one out of 10 times. Out of a shipment of n = 200 lotto tickets, using the Poisson distributions in each case (for a, b and c), find the probability for the lotto tickets that there are: a. somewhere between 75 and 95 prizes. b. somewhere between 15 and 25 prizes. c. more than 50 prizes d.If a customer keeps buying tickets till she finds a winner, find the probability that her 10^th ticket will be a winner.

Each of three barrels from a manufacturing line are classified as either above (a) or below (b) the target weight. Provide the ordered sample space.

7. An online poll at a popular web site asked the following:

   A nationwide ban of the diet supplement ephedra went into effect recently. The herbal stimulant has been linked to 155 deaths and many more heart attacks and strokes. Ephedra manufacturer NVE Pharmaceuticals, claiming that the FDA lacked proof that ephedra is dangerous if used as directed, was denied a temporary restraining order on the ban yesterday by a federal judge. Do you think that ephedra should continue to be banned nationwide?

   65% of the 17,303 respondents said “yes.” Comment on each of the following statements about this poll in one or two complete sentences.

   1. (a) With a sample size that large, we can be pretty certain we know the true proportion of Americans who think ephedra should be banned.

   2. (b) The wording of the question is clearly very biased.

   3. (c) The sampling frame is all Internet users.

   4. (d) This is a voluntary response survey, so the results can’t be reliably generalized to any population of interest.

Describe how and why you should partition your data when using classification techniques like k-nearest neighbors and logistic regression.

Eight pawns are placed at random on an 8 × 8 chessboard, with all configurations equally likely. What is the probability of each of these events:

1. The pawns are in a straight line. (Don’t forget the diagonals!)

2. All the pawns occupy white squares.

3. No two pawns share the same row.

4. Now two pawns share the same row or the same column.

7. A student measures the mass percent chloride in their unknown four times by each of two methods. (a) Find the mean, standard deviation, and 95% confidence limit for each method. (b) Determine if each method’s result is “significantly” different from the expected value of 48.86% Chloride. (c) Use the F test to decide whether the standard deviations are “significantly” different. (d) Use the t test to decide whether the means are different from one another at the 95% confidence level.

Method Replicate Measurements

A 47.62% 47.91% 47.83% 47.79% 48.01%

B 47.11% 49.63% 48.72% 49.17% 47.99%

A manufacturer of television sets is interested in the effect on tube conductivity of four different types of coating for color picture tubes. A completely randomized experiment is conducted, and the following conductivity data are obtained:

a) Is there a difference in conductivity due to a coating type? Use α= 0.05.

b) Estimate the overall mean and the treatment effects.

c) Calculate a confidence interval with 95% for the average coating type 4 and calculate the confidence interval with 99% for the difference between the average coating types 1 and 4.

d) Test all pairs of means using the Fisher LSD method with α= 0.05.

e) Use the graphical method discussed in section 3-5.3 to compare the means. What is the type of coating which produces the highest conductivity?

f) Assuming that coating type 4 is currently being used, what would you recommend to manufacturer? It wants to minimize conductivity.

g) Analyze the residuals and draw conclusions about the adequacy of the model.

Let t 0 be a specific value of t. Use the table of critical values of t below to find t 0 dash values such that following statements are true. a. Upper P left parenthesis t greater than or equals t 0 right parenthesisequals​.025, where dfequals11 b. Upper P left parenthesis t greater than or equals t 0 right parenthesisequals​.01, where dfequals18 c. Upper P left parenthesis t less than or equals t 0 right parenthesisequals​.005, where dfequals7 d. Upper P left parenthesis t less than or equals t 0 right parenthesisequals​.05, where dfequals14 LOADING... Click the icon to view the table of critical values of t.

7. Two fair six sided dice are rolled.

(i) What is the probability that the sum of the two results is 6?
(ii) What is the probability that the larger value of the two results is 4?

(iii) What is the probability that the both results are at most 4?
(iv) What is the probability that the number 3 appears at least once?

This exercise must be completed on the four subscales below, and you should, therefore, produce four reliability analyses. o Subscale 1 (Fearof statistics): items 1, 3, 4, 5, 12, 16, 20, 21 o Subscale 2 (Peerevaluation): items 2, 9, 19, 22, 23 o Subscale 3 (Fearof computers): items 6, 7, 10, 13, 14, 15, 18 o Subscale 4 (Fear of mathematics): items 8, 11, 17

(1) For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.

In a random sample of 70 professional actors, it was found that 45 were extroverts.

(a) Let p represent the proportion of all actors who are extroverts. Find a point estimate for p. (Round your answer to four decimal places.)


(b) Find a 95% confidence interval for p. (Round your answers to two decimal places.)

(2) For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.

A random sample of 5,100 permanent dwellings on an entire reservation showed that 1,641 were traditional hogans.

(a) Let p be the proportion of all permanent dwellings on the entire reservation that are traditional hogans. Find a point estimate for p. (Round your answer to four decimal places.)

(b) Find a 99% confidence interval for p. (Round your answer to three decimal places.)

lower limit ____

upper limit ____

(3) For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.

In a random sample of 520 judges, it was found that 282 were introverts.

(a) Let p represent the proportion of all judges who are introverts. Find a point estimate for p. (Round your answer to four decimal places.) ______


(b) Find a 99% confidence interval for p. (Round your answers to two decimal places.)

The following data shows the price of PAO, Inc. stock over the last eight months. Month Price ($) 1 2.44 2 2.44 3 2.45 4 2.43 5 2.44 6 2.45 7 2.44 8 2.47 2. What kind of relationship exists between stock price and time (negative, positive, or no relation)? 3. In month 4, a new marketing campaign began. If stock price is an indicator of the campaign's success, was the campaign a success?