A new car dealer calculates that the dealership must average more than 4.5% profit on sales of new cars. A random sample of 81 cars yielded a sample mean of 4.97% profit and a sample standard deviation of 1.8%. Using a significance level of α = .05, does the sample data provide evidence to conclude that the dealership averages more than 4.5% profit on sales of new cars?

A. Yes, because the the sample mean is more than 4.5%.

B. Yes, because p = .0106 is less than .05.

C. No, because t = 2.35 is more than 1.645

D. No, because the p-value is less than the critical value

Water specimens are taken from water used for cooling as it is being discharged from a power plant into a river. It has been determined that as long as the mean temperature of the discharged water is at most 150°F, there will be no negative effects on the river's ecosystem. To investigate whether the plant is in compliance with regulations that prohibit a mean discharge water temperature above 150°F, researchers will take 50 water specimens at randomly selected times and record the temperature of each specimen. The resulting data will be used to test the hypotheses

H₀: μ = 150°F

versus

H_a: μ > 150°F.

(a) In the context of this example, describe Type I and Type II errors. (Select all that apply.)

A Type I error is not obtaining convincing evidence that the mean water temperature is greater than 150°F when in fact it is greater than 150°F.

A Type I error is obtaining convincing evidence that the mean water temperature is greater than 150°F when in fact it is (at most) 150°F.

A Type II error is obtaining convincing evidence that the mean water temperature is greater than 150°F when in fact it is (at most) 150°F.

A Type II error is not obtaining convincing evidence that the mean water temperature is greater than 150°F when in fact it is greater than 150°F.

A magazine collects data each year on the price of a hamburger in a certain fast food restaurant in various countries around the world. The price of this hamburger for a sample of restaurants in Europe in January resulted in the following hamburger prices (after conversion to U.S. dollars).

The mean price of this hamburger in the U.S. in January was $4.61. For purposes of this exercise, assume it is reasonable to regard the sample as representative of these European restaurants. Does the sample provide convincing evidence that the mean January price of this hamburger in Europe is greater than the reported U.S. price? Test the relevant hypotheses using

α = 0.05.

(Use a statistical computer package to calculate the P-value. Round your test statistic to two decimal places and your P-value to three decimal places.)

Medical research has shown that repeated wrist extension beyond 20 degrees increases the risk of wrist and hand injuries. Each of 24 students at a university used a proposed new computer mouse design. While using the mouse, each student's wrist extension was recorded. Data consistent with summary values given in a paper are given. Use these data to test the hypothesis that the mean wrist extension for people using this new mouse design is greater than 20 degrees. (Use

α = 0.05.

Use a statistical computer package to calculate the P-value. Round your test statistic to two decimal places and your P-value to three decimal places.)

Each round of game played by a gambler is either a win with probability p or a loss with probability 1 − p. If the round is a win, then a random amount of money having an exponential distribution with rate λ will be awarded to the gambler. If the round is a loss, then he loses everything that had been accumulated up to that time and cannot play any additional rounds. After a win round, the gambler can either choose to quit and keep whatever has been won or can choose to play another round. Suppose that a gambler plans to continue playing until either his total winnings exceeds t or a loss occurs.

(a) What is the expectation of N, the number of winning rounds that it would take until his fortune 1 exceeds t?

(b) What is the probability he will successfully reach a fortune of at least t?

Not handwriting answer, please

In a word document, please answer the following questions:

Course Introduction of Biostatistics

Define the following terms:
correlation coefficient
scatter plot
bivariate relationship
Provide an example where the outlier is more important to the research than the other observations?
Identify when to use Spearman’s rho.

In a study of the accuracy of fast food​ drive-through orders, Restaurant A had 231

accurate orders and

74

that were not accurate.a. Construct a

95​%

confidence interval estimate of the percentage of orders that are not accurate.b. Compare the results from part​ (a) to this

95​%

confidence interval for the percentage of orders that are not accurate at Restaurant​ B:

0.2160 <p<0.319

What do you​ conclude?

a. Construct a

95​%

confidence interval. Express the percentages in decimal form.

nothing less than<pless than<nothing

​(Round to three decimal places as​ needed.)

To navigate on Lake Latte (fed by the Decaf and the Vanilla Rivers) at least two of the three
radio navigation beacons must be working. If the probability that a beacon is working is
p and the operational status of each station is independent of the other two, what is the
probability of being able to navigate on the lake? What is the probability that beacon #2 is
working if navigation on the lake is possible?

In any given year, one in three Americans over the age of 65 will experience a fall. If you have three living grandparents over the age of 65, and assuming that the probability of a fall for each grandparent is independent:

a. What is the probability that none of the three grandparents will experience a fall? Provide your answer as a decimal between 0 and 1. Hint: Your sample size is 3, what is the number of successes.

b. What is the probability that one or more grandparents will experience a fall? Provide your answer as a decimal between 0 and 1.

1. Given an equilateral triangle ABC with a side of 5 cm. Find the probability that a point taken at random will be located from point A at a distance greater than 2 cm.

2. There are two boxes: inside the first 10 white and 15 black balls, inside the second 10 white and 10 black balls. 5 balls are transferred from the first box to the second and then one ball is removed from the second box at random, what is the probability that it is white?

Thanks Sir )

2.38 Baggage fees: An airline charges the following baggage fees: $25 for the first bag and an extra $35 for the second. Suppose 54% of passengers have no checked luggage, 34% have only one piece of checked luggage and 12% have two pieces. We suppose a negligible portion of people check more than two bags.


a) The average baggage-related revenue per passenger is: $  (please round to the nearest cent)
b) The standard deviation of baggage-related revenue is: $  (please round to the nearest cent)
c) About how much revenue should the airline expect for a flight of 120 passengers? $  (please round to the nearest dollar)

In the article “Explaining an Unusual Allergy,” appearing on the Everyday Health Network, Dr. A Feldweg explained that allergy to sulfites is usually seen in patients with asthma. The typical reaction is a sudden increase in asthma symptoms after eating a food containing sulfites. Studies are performed to estimate the percentage of the nation’s 10 million asthmatics who are allergic to sulfites. In one survey, 38 of 500 randomly selected U.S. asthmatics were found to be allergic to sulfites.
(Source: Elementary Statistics, Weiss, 8th Edition)

If you were to construct a 98% confidence interval for the proportion of all U.S. asthmatics who are allergic to sulfites, what is the margin of error used to calculate the interval? (use the standard error found in problem 1, round your critical value to the hundredths place, and round the margin of error to the thousandths place)

find the critical value (or values) for the t test for each. a. n = 12, a = 0.01, left tailed, b. n = 16, a = 0.05, right tailed, c. n = 7, a = 0.10, two tailed, d. n - 11, a - 0.025, right tailed, e. n = 10, a = 0.05, two tailed

The time needed for checking in at a hotel is to be investigated. Historically, the process has had a standard deviation equal to .146. The means of 39 samples of n = 17 are

a-1. Construct an x⎯⎯x¯ -chart for this process with three-sigma limits. (Do not round intermediate calculations. Round your answers to 2 decimal places.)
  

a-2. Is the process in control?

• Yes

• No

b. Analyze the data using a median run test and an up/down run test. What can you conclude?

rev: 04_08_2019_QC_CS-165352

Problem 1

An automobile manufacturer employs sales representatives who make calls on dealers. The manufacturer wishes to compare the effectiveness of four different call-frequency plans for the sales representatives. Thirty-two representatives are chosen at random from the sales force and randomly assigned to the four call plans (eight per plan). The representatives follow their plans for 6 months, and their sales for the 6-month study period are recorded. These data are listed in the file P19_01.xlsx.

Do the sample data support the hypothesis that at least one of the call plans helps produce a higher average level of sales? Perform an appropriate statistical test and report a p-value.

If the sample data indicate the existence of mean sales differences across the call plans, which plans produce significantly different average sales levels at the 95% level?

the data:

please, i need the answer by using SPSS program. if you display the steps, it will be appreciated.

The authors of a paper describe an experiment to evaluate the effect of using a cell phone on reaction time. Subjects were asked to perform a simulated driving task while talking on a cell phone. While performing this task, occasional red and green lights flashed on the computer screen. If a green light flashed, subjects were to continue driving, but if a red light flashed, subjects were to brake as quickly as possible. The reaction time (in msec) was recorded. The following summary statistics are based on a graph that appeared in the paper.

n = 49     

x = 525

     s = 70

(a)

Construct a 95% confidence interval for μ, the mean time to react to a red light while talking on a cell phone. (Round your answers to three decimal places.)

Interpret a 95% confidence interval for μ, the mean time to react to a red light while talking on a cell phone.

There is a 95% chance that the true difference in the mean time to react to a red light while talking on a cell phone is directly in the middle of these two values. There is a 95% chance that the true mean time to react to a red light while talking on a cell phone is directly in the middle of these two values.     We are 95% confident that the mean time to react to a red light while talking on a cell phone is between these two values. We are 95% confident that the true mean time to react to a green light while talking on a cell phone is directly in the middle of these two values. We are 95% confident that the true mean time to react to a green light while talking on a cell phone is between these two values.

(b)

What assumption must be made in order to generalize this confidence interval to the population of all drivers?

The assumption that the subjects of the experiment formed a random sample from the population of drivers. The assumption that the subjects of the experiment formed the population of drivers.     The assumption that the experiment captured the population of drivers. The assumption that the subjects of the experiment formed the population of distracted drivers. The assumption that the subjects of the experiment formed a random sample from the population of distracted drivers.

(c)

Suppose that the researchers wanted to estimate the mean reaction time to within 6 msec with 95% confidence. Using the sample standard deviation from the study described as a preliminary estimate of the standard deviation of reaction times, compute the required sample size. (Round your answer up to the nearest whole number.)

n =

You may need to use the appropriate table in Appendix A to answer this question.