The computer operations department had a business objective of reducing the amount of time to fully update each subscriber's set of messages in a special secured email system. An experiment was conducted in which 23 subscribers were selected and three different messaging systems were used. Eight subscribers were assigned to each system, and the update times were measured as follows:

Given Sample Means: x̅a = 41.46, x̅b = 36.33, x̅c = 35.84, Grand Mean = 38.29

Given Sample Standard Deviations: sa = 4.32, sb = 4.00, sc = 3.02, S = 4.34

A) At the 0.05 level of significance, is there evidence of a difference in the variance of the update times between Systems B and C? (Show your work: hypotheses, test statistic, critical value, and decision).

B) Fill out the following summary table for One-Way ANOVA:

C) Using the Tukey-Kramer method, determine which pair of the designs have the difference in mean distances at the 0.05 level of significance by filling out the following table (the upper-tail critical value from the studentized range distribution with 3 and 20 degrees of freedom as Qα = 3.578)

Please do not use this as an example: Suppose a company printed baseball cards. It claimed that 30% of its cards were rookies; 60% were veterans but not All-Stars; and 10% were veteran All-Stars.

When evaluating a chi-square test, describe the importance of the goodness of fit test. Provide an example and explain how the test is used to evaluate the data.

Cholesterol levels for a group of women aged 30-39 follow an approximately normal distribution with mean 190.14 milligrams per deciliter (mg/dl). Medical guidelines state that women with cholesterol levels above 240 mg/dl are considered to have high cholesterol and about 9.3% of women fall into this category.

1. What is the Z-score that corresponds to the top 9.3% (or the 90.7-th percentile) of the standard normal distribution? Round your answer to three decimal places.

2. Find the standard deviation of the distribution in the situation stated above. Round your answer to 1 decimal place.

3. For each dataset, what is the unit of observation? What is/are the variable(s) collected? State whether the distribution of this data will be skewed and explain why. Draw a plausible sketch of the distribution and label the axes.

a. Lengths of pant legs cut and sewn to be 32 inches long.

b. The times for students in an introductory psychology course to complete a difficult one-hour timed exam.

A drug study compared the amounts of nitrate absorbed into the skin for brand name and generic formulations of the drug. The two drugs were both applied to the arms of 14 participants, and the amounts absorbed, in mg/cm³, were measured. Does the mean amount absorbed differ between the generic and brand name drug? Use formal hypothesis testing.

A youth and money survey, sponsored by the american savings education council talked to 1,000 students about their personal finance, ages 16-22. The survey found that 33% of students in this age group have their own credit card. if a sub sample of 100 students is taken from this survey what is the probability that 40 or less will have their own credit card?

A.) Using the normal approximation for the binomial solve this problem, show all of your work in solving the problem.

A new production process is being contemplated for the manufacture of stainless steel bearings. Measurements of the diameters of random samples of bearings from the old and new processes produced the following data (all in mm): Old

.

A. Can you conclude that the variances between the new and old procedure are different? Use formal hypothesis testing.

b. Can you conclude that there is a difference in mean diameter between the procedures? Use formal hypothesis testing.

c. Management wants to know if the new procedure is comparable to the old procedure. What can you tell them? (Give a yes/no answer and your reasoning, based on statistics.)

In a certain​ country, the true probability of a baby being a

girl

is

0.461

Among the next

four

randomly selected births in the​ country, what is the probability that at least one of them is a

boy​?

The probability is.

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

Are nursing salaries in City A lower than those in City B? As reported by a newspaper, salary data show staff nurses in City A earn less than staff nurses in City B. Suppose that in a follow-up study of 40 staff nurses in City A and 50 staff nurses in City B you obtain the following results. Assume population variances are unknown and unequal.

(a)

Formulate hypotheses so that, if the null hypothesis is rejected, we can conclude that salaries for staff nurses in City A are significantly lower than for those in City B. Use

α = 0.05.

H₀: μ₁ − μ₂ = 0

H_a: μ₁ − μ₂ < 0

H₀: μ₁ − μ₂ < 0

H_a: μ₁ − μ₂ ≠ 0

H₀: μ₁ − μ₂ ≤ 0

H_a: μ₁ − μ₂ > 0

H₀: μ₁ − μ₂ > 0

H_a: μ₁ − μ₂ = 0

H₀: μ₁ − μ₂ ≠ 0

H_a: μ₁ − μ₂ = 0

(b)

What is the value of the test statistic? (Round your answer to three decimal places.)

(c)

What is the p-value? The degrees of freedom for this test are 87. (Round your answer to four decimal places.)

p-value =

Compare the firstplace finish times for men and women. If the 53 men and women runners had competed as one group, in what place would winner of women's marathon have finished? Round your answer to 2 decimal places.

The first place runner in the men’s group finished  minutes _______aheadbehind of the first place runner in the women’s group.

b. What is the median time for men and women runners? Compare men and women runners based on their median times. Round your answers to 2 decimal places.

Using the median finish times, the men’s group finished  minutes _______aheadbehind of the women’s group.

c. Provide a five-number summary for both the men and the women. Round your answers to 2 decimal places.

d. Are there outliers in either group?

If data contain outliers enter the value. If there no outliers live answer blank. If there is more than one value, separate your answers with commas (to 2 decimals).

Outliers in the men's group.

Outliers in the women's group.

e. Which of the following box plots accurately displays the data set?

_________Box plot #1Box plot #2Box plot #3Box plot #4

Did men or women have the most variation in finish times?

_______MenWomen

please be very specific on showing work done!!

If Z∼N(μ=0,σ2=1)Z∼N(μ=0,σ2=1), find the following probabilities:

1. P(Z<1.58)=P(Z<1.58)=
2. P(Z=1.58)=P(Z=1.58)=
3. P(Z>−.27)=P(Z>−.27)=
4. P(−1.97<Z<2.46)=

Qualitative, Quantitative, Discrete, Continuous.

Required:

(a) List 5 qualitative variables and 5 quantitative variables seen around the home.

(b) List 5 discrete and 5 continuous variables found at home, at work, on TV or any other location.

In each case explain the reason(s) for your answers.  

1. 7 During the period of time that a local university takes phone-in registrations, calls come in at the rate of one every two minutes.
   1. What is the probability of receiving NO calls in a 10-minute period?
   2. What is the probability of receiving more than five calls in a 10-minute period?
   3. What is the probability of receiving less than seven calls in 15-minutes?
   4. What is the probability of receiving at least three but no more than 10 calls in 12 minutes?

USING EXCEL

A marketing firm wants to know how strongly Cuyahoga County residents support building a new stadium for the local national football league team, the Cleveland Browns. They get a complete list of all residents in Cuyahoga County, along with their addresses and phone numbers.   There are 52 zip codes in the county. From each of those zip codes, 10 Cuyahoga County residents are randomly selected and surveyed.

1. Describe the population.

2. What is the sample?

3. What type of sampling design was used? Explain.