Suppose that the weight of seedless watermelons is normally distributed with mean 6.3 kg. and standard deviation 1.1 kg. Let X be the weight of a randomly selected seedless watermelon. Round all answers to 4 decimal places where possible.

a. What is the distribution of X? X ~ N( , )

b. What is the median seedless watermelon weight? kg.

c. What is the Z-score for a seedless watermelon weighing 6.9 kg?

d. What is the probability that a randomly selected watermelon will weigh more than 5.9 kg?

What is the probability that a randomly selected seedless watermelon will weigh between 5.7 and 6.6 kg?

The 70th percentile for the weight of seedless watermelons is kg.?

Accountant Ian Somnia's infamous napping at work has given rise to a challenge from colleague I. M. Tarde. At the company retreat, the two will take turns trying to stay awake during a sequence of 5-minute company training films. The probability that Somnia will fall asleep during a given film is 0.8, while the probability that Tarde does is 0.7. The first one to stay awake (as determined by a panel of alert judges) wins a $1000 bonus. If Somnia and Tarde alternate watching films, with Somnia going first, what are the chances that Tarde wins the bonus? (Hint: A typical sequence of films for which Tarde wins the bonus is NNNY, where N = “not awake” and Y = “awake.”)

Explain the five-step process for evaluating a multiple regression model.

Regarding the T distribution

a. its precise shape is determined by whether its a repeated measures t test or an independent samples T test

b. none of the answers are correct.

c. the shape is fixed, it does not change at all.

d. As sample size gets larger, the critical value of T gets smaller.

A person's blood glucose level and diabetes are closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. Suppose that after a 12-hour fast, the random variable x will have a distribution that is approximately normal with mean μ = 82 and standard deviation σ = 27. Note: After 50 years of age, both the mean and standard deviation tend to increase. For an adult (under 50) after a 12-hour fast, find the following probabilities. (Round your answers to four decimal places.) (a) x is more than 60 (b) x is less than 110 (c) x is between 60 and 110 (d) x is greater than 125 (borderline diabetes starts at 125)

In a typical month, men spend $178 and women spend $96 on leisure activities according to results from an International Communications Research (ICR) for American Express poll, as reported in USAToday June 25, 2015. Suppose random samples of 100 men and 100 women were taken from the population of male and female college students. Each student was asked to determine his or her expenditures for leisure activities in the prior month. The sample data results had a standard deviation of $75 for the men and $50 for the women.

A. Assuming normality in leisure activity expenditures, is the difference found in the ICR poll significant at alpha = .05?
B. Construct a 95% confidence interval for the difference in the expenditures. Interpret this interval.

What appear to be the 3-4 most important car specifications for predicting the car’s price? using the toyotacorolla file

A simple random sample of 60 items resulted in a sample mean of 90. The population standard deviation is σ = 10. (a) Compute the 95% confidence interval for the population mean. (Round your answers to two decimal places.) (b) Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean. (Round your answers to two decimal places.)

A consumer price analyst claims that prices for liquid crystal display (LCD) computer monitors have a mean of $ 170 and a standard deviation of $ 47.

2. You randomly selected 25 LCD compute monitors. What is the probability that their mean cost is less than $ 180? Assume here that the prices are normally distributed

3. You randomly selected 64 LCD compute monitors. What is the probability that their mean cost is less than $ 180?

Sleep – College Students: Suppose you perform a study about the hours of sleep that college students get. You know that for all people, the average is about 7 hours. You randomly select 35 college students and survey them on their sleep habits. From this sample, the mean number of hours of sleep is found to be 6.1 hours with a standard deviation of 0.97 hours. You want to construct a 99% confidence interval for the mean nightly hours of sleep for all college students.

(a) What is the point estimate for the mean nightly hours of sleep for all college students?
hours

(b) Construct the 99% confidence interval for the mean nightly hours of sleep for all college students. Round your answers to 1 decimal place.
< μ <

(c) Are you 99% confident that the mean nightly hours of sleep for all college students is below the average for all people of 7 hours per night? Why or why not?

Yes, because 7 is above the upper limit of the confidence interval for college students.No, because 7 is below the upper limit of the confidence interval for college students.    Yes, because 7 is below the upper limit of the confidence interval for college students.No, because 7 is above the upper limit of the confidence interval for college students.

(d) We are never told whether or not the parent population is normally distributed. Why could we use the above method to find the confidence interval?

Because the margin of error is less than 30.Because the margin of error is positive.    Because the sample size is less than 100.Because the sample size is greater than 30.

Bass - Samples: The bass in Clear Lake have weights that are normally distributed with a mean of 2.3 pounds and a standard deviation of 0.9 pounds.

(a) If you catch 3 random bass from Clear Lake, find the probability that the mean weight is less than 1.0 pound. Round your answer to 4 decimal places.


(b) If you catch 3 random bass from Clear Lake, find the probability that the mean weight it is more than 3 pounds. Round your answer to 4 decimal places.

A pharmaceutical manufacturer purchases a particular material from two different suppliers. The mean level of impurities in the raw material is approximately the same for both suppliers, but the manufacturer is concerned about the variability of the impurities from shipment to shipment. To compare the variation in percentage impurities for the two suppliers, the manufacturer selects 9 shipments from each of the two suppliers and measures the percentage of impurities in the raw material for each shipment. The sample means and variances are shown in the table.

(a) Do the data provide sufficient evidence to indicate a difference in the variability of the shipment impurity levels for the two suppliers? Test using α = 0.01. Based on the results of your test, what recommendation would you make to the pharmaceutical manufacturer?

State the null and alternative hypotheses.

H₀: σ₁² = σ₂² versus H_a: σ₁² < σ₂²

H₀: σ₁² = σ₂² versus H_a: σ₁² ≠ σ₂²   

H₀: σ₁² < σ₂² versus H_a: σ₁² > σ₂²

H₀: σ₁² ≠ σ₂² versus H_a: σ₁² = σ₂²

H₀: σ₁² = σ₂² versus H_a: σ₁² > σ₂²

State the test statistic. (Round your answer to two decimal places.)
F =  

State the rejection region. (Round your answer to two decimal places.)
F >  

State the conclusion.

H₀ is rejected. There is insufficient evidence to indicate that the supplier's shipments differ in variability.

H₀ is rejected. There is sufficient evidence to indicate that the supplier's shipments differ in variability.   

H₀ is not rejected. There is sufficient evidence to indicate that the supplier's shipments differ in variability.

H₀ is not rejected. There is insufficient evidence to indicate that the supplier's shipments differ in variability.

(b) Find a 99% confidence interval for σ₂². (Round your answers to three decimal places.)

Interpret your results.

In repeated sampling, 1% of all intervals constructed in this manner will enclose σ₂².

There is a 1% chance that an individual sample variation will fall within the interval limits.   

There is a 99% chance that an individual sample variation will fall within the interval.99% of all values will fall within the interval limits.

In repeated sampling, 99% of all intervals constructed in this manner will enclose σ₂².

In a recent study, 35% of people surveyed indicate chocolate was their favorite flavor of ice cream. Suppose we select a sample of 8 people and ask them to name their favorite flavor of ice cream.

How many of those in the sample would you expect to name chocolate? (Round your answer to 1 decimal place.)

What is the probability exactly four of those in the sample name chocolate? (Round the probability to 5 decimal places and the final answer to 4 decimal places.)

What is the probability four or more name chocolate? (Round your probability to 4 decimal places.)

1. An experimenter investigated the effects of sensitivity training on police officers’ effectiveness at resolving domestic disputes.  She randomly sampled a group of police officers who had completed a sensitivity course and a group of officers who had not.  Participants were tested on their ability to successfully resolve a simulated domestic dispute.  The scores below were obtained.  Test the researcher’s hypothesis with α = .0

1. Use the 5-step procedure test the hypothesis. (22 points)
2. Calculate the 99% confidence interval.  (4 points)
3. Calculate and estimate the effect size. (4 points)
4. Using the appropriate power table in the textbook, what is the approximate power of this test?  Discuss at least three ways that you could increase the power of the test.    (10 points)
5. (This is for psychology statistics t-tests) (i had already asked this question once before and they noted that i needed more information about a power table however this is all the information i was provided and not sure what power table to include)

Let X be Binomial(94,0.43) distributed. Use Chebyshev's inequality to estimate P(X ≥ 55).

answer: 0.1084

Let X be Geometric with parameter 0.28. Use Chebyshev's inequality to estimate P(X ≥ 19).

answer: 0.0386

Let X be uniformly distributed on {1,...,35}. Use Chebyshev's inequality to estimate P(X ≥ 35).

answer: 0.3529

Let X be Poisson-distributed with parameter 0.6. Use Chebyshev's inequality to estimate P(X ≥ 13).

answer:0.0039