The data set contains the compressive strength, in thousands of pounds per square inch (psi), of 30 samples of concrete taken two and seven days after pouring.

(a) At the 0.10 level of significance, is there evidence of a difference in the mean strengths at two days and at seven days?

(b) Find the p-value in (a) and interpret its meaning.

(c) At the 0.10 level of significance, is there evidence that the mean strength is lower at two days than at seven days?

(d) Find the p-value in (c) and interpret its meaning.

A tire manufacturer produces tires that have a mean life of at least 30000 miles when the production process is working properly. The operations manager stops the production process if there is evidence that the mean tire life is below 30000 miles.

The testable hypotheses in this situation are H0:μ=30000H0:μ=30000 vs HA:μ<30000HA:μ<30000.

1. Identify the consequences of making a Type I error.
A. The manager stops production when it is not necessary.
B. The manager stops production when it is necessary.
C. The manager does not stop production when it is not necessary.
D. The manager does not stop production when it is necessary.

2. Identify the consequences of making a Type II error.
A. The manager stops production when it is necessary.
B. The manager does not stop production when it is necessary.
C. The manager does not stop production when it is not necessary.
D. The manager stops production when it is not necessary.

To monitor the production process, the operations manager takes a random sample of 30 tires each week and subjects them to destructive testing. They calculate the mean life of the tires in the sample, and if it is less than 29000, they will stop production and recalibrate the machines. They know based on past experience that the standard deviation of the tire life is 2750 miles.

3. What is the probability that the manager will make a Type I error using this decision rule? Round your answer to four decimal places.

4. Using this decision rule, what is the power of the test if the actual mean life of the tires is 28750 miles? That is, what is the probability they will reject H0H0 when the actual average life of the tires is 28750 miles? Round your answer to four decimal places.

1) Distinguish between Time Series models and Causal models. The different types of control charts and reasons for their use. Provide a working example of each in the auto manufacturing industry.

2) Discuss each of the basic patterns mentioned by the authors for Time Series Models. Provide an example of each.

3) Distinguish between Simple Moving Average and Weighted Moving Average. What are their benefits and how are these applied in the real world?

4) Distinguish between low and high α values and what they represent in Exponential Smoothing.

5) Distinguish between linear regression and correlation. Provide a working example of each in business.

You’re waiting for Caltrain. Suppose that the waiting times are approximately Normal with a mean of 12 minutes and a standard deviation of 3 minutes. Use the Empirical Rule to estimate each of the following probabilities without using the normalcdf function of your calculator:

a) What is the probability that you’ll wait between 9 and 15 minutes for the train?

b) What is the probability that you’ll wait between 6 and 18 minutes for the train?

c) What is the probability that you’ll wait between 3 and 21 minutes for the train?

d) What is the probability that you’ll wait more than 12 minutes for the train?

e) What is the probability that you’ll wait between 12 and 18 minutes for the train?

f) What is the probability that you’ll wait between 3 and 18 minutes for the train?

g) What is the probability that you’ll wait more than 21 minutes for the train?

Please show your work.

A. If a normal distribution of scores has a mean of 100 and a standard deviation of 10, what percentage of scores would lie below 70? a. 0.13%. b.2.15%. c. 2.28% d. 99.87%

B. What percentage of scores lie between 85 and 100 for a normal distribution with a mean of 100 and a standard deviation of 15? a. +15% b.-15% c.34.13% d. -34.13%

C What percentage of scores lie between 70 and 80 for a normal distribution with the mean of 100 and a standard deviation of 10? a.+27% b.-13% c.-7%. d. 2.15%.

Iconic memory is a type of memory that holds visual information for about half a second (0.5 seconds). To demonstrate this type of memory, participants were shown three rows of four letters for 50 milliseconds. They were then asked to recall as many letters as possible, with a 0-, 0.5-, or 1.0-second delay before responding. Researchers hypothesized that longer delays would result in poorer recall. The number of letters correctly recalled is given in the table.

(a) Complete the F-table. (Round your values for MS and F to two decimal places.)

(b) Compute Tukey's HSD post hoc test and interpret the results. (Assume alpha equal to 0.05. Round your answer to two decimal places.)

The critical value is for each pairwise comparison.

Which of the comparisons had significant differences? (Select all that apply.)

Recall following no delay was significantly different from recall following a one second delay. The null hypothesis of no difference should be retained because none of the pairwise comparisons demonstrate a significant difference. Recall following no delay was significantly different from recall following a half second delay. Recall following a half second delay was significantly different from recall following a one second delay.

The number of chocolate chips in a an 18-ounce bag of Chips Ahoy! Chocolate chip cookies is approximately normally distributed, with a mean of 1262 chips and a standard deviation of 118 chips, according to a study by cades of the US Air Force Academy.

1. What proportion of 18 ounce bags has more than 1000 chips?

On a multiple choice examination, each question has exactly five options, of which the student must pick one. Only one option is correct for each question. If the student is merely guessing at the answer, each option should be equally likely to be chosen. Given that the test has 18 questions, and that a student is just guessing on each question, find the probability of the following events: (a) exactly three are correct, (b) fewer than five are correct, (c) between two and sever answers are correct.

Please answer these questions in detail. With formulas

A new blood clotting drug has been developed and researcher are interested to see if the new drug out performs the most commonly used treatment. 6 patients were given the new drug and 7 patients were given the old drug. The clotting times were recorded (lower times are better). The data are:

1: What is the null hypothesis?

a: there is no difference in clotting times

b: the old drug clots faster

c: the new drug clots faster

d: there is a difference in clotting times

2: What is the value of the test statistic?

3: How many degrees of freedom are there?

4: What we conclude if we ran a two tailed test?

a: there is no evidence of a difference in clotting times

b: there is evidence that the new drug results in faster clotting

c: there is evidence that the old drug results in faster clotting

5: What would we conclude if we had instead used a one-tailed test?

a: there is no evidence of a difference in clotting times

b: there is evidence that the new drug results in faster clotting

c: there is evidence that the old drug results in faster clotting

Assume that x is a binomial random variable with n = 100 and p = 0.40. Use a normal
approximation (BINOMIAL APPROACH) to find the following: **please show all work**
c. P(x ≥ 38) d. P(x = 45) e. P(x > 45) f. P(x < 45)

A random sample of n = 25 is selected from a normal population with mean

μ = 101

and standard deviation

σ = 13.

(a) Find the probability that x exceeds 107. (Round your answer to four decimal places.)

(b) Find the probability that the sample mean deviates from the population mean μ = 101 by no more than 2. (Round your answer to four decimal places.)

Suppose x has a distribution with μ = 19 and σ = 18. (a) If a random sample of size n = 46 is drawn, find μx, σ x and P(19 ≤ x ≤ 21). (Round σx to two decimal places and the probability to four decimal places.) μx = σ x = P(19 ≤ x ≤ 21) = (b) If a random sample of size n = 64 is drawn, find μx, σ x and P(19 ≤ x ≤ 21). (Round σ x to two decimal places and the probability to four decimal places.) μx = σ x = P(19 ≤ x ≤ 21) = (c) Why should you expect the probability of part (b) to be higher than that of part (a)? (Hint: Consider the standard deviations in parts (a) and (b).) The standard deviation of part (b) is part (a) because of the sample size. Therefore, the distribution about μx is . Need Help? Read It

When crossing the Golden Gate Bridge traveling into San Francisco, all drivers must pay a toll. Suppose the amount of time (in minutes) drivers wait in line to pay the toll follows an exponential distribution with a probability density function of f(x) = 0.2e−0.2x.

a. What is the mean waiting time that drivers face when entering San Francisco via the Golden Gate Bridge?

b. What is the probability that a driver spends more than the average time to pay the toll? (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.)

c. What is the probability that a driver spends more than 10 minutes to pay the toll? (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.) d. What is the probability that a driver spends between 4 and 6 minutes to pay the toll? (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.)

The probability of a telesales representative making a sale on a customer call is 0.15.Find the probability that......

A) No sales are made in 10 calls

B) more than 3 sales are made in 10 calls.

C) How many representatives are required to achieve a mean of at least 5 sales each day?