There are three hospitals in the Tulsa, Oklahoma, area. The following data show the number of outpatient surgeries performed on Monday, Tuesday, Wednesday, Thursday, and Friday at each hospital last week. At the 0.01 significance level, can we conclude there is a difference in the mean number of surgeries performed by hospital or by day of the week?

A sample of 1600 computer chips revealed that 47% of the chips fail in the first 1000 hours of their use. The company's promotional literature states that 44% of the chips fail in the first 1000 hours of their use. The quality control manager wants to test the claim that the actual percentage that fail is different from the stated percentage. Is there enough evidence at the 0.01 level to support the manager's claim?

7) Personal phone calls received in the last three days by a new employee were 4, 1, and 8. Assume that samples of size 2 are randomly selected with replacement from this population of three values. a) List the nine different possible samples of size 2 and find the mean of each of them. b) The probability for each sample mean in Part a) is 1/9. Summarize your results in Part a) by construct ing a sampling distribution for these sample means. c) Find the expected value based on Part b). This expected value is also the mean of all the nine sample means found in Part a). d) Find the population mean of the personal phone calls received in the last three days by a new employee: {2, 3, 7} and compare it with your result in Part c).

The distribution of birthweight of singletons in city of Tianjin, China is approximately normal with mean m=3,445 grams and standard deviation = 409 grams [2]. An investigator plans to conduct a study to determine if birthweight for singletons whose mothers were with gestational diabetes mellitus (GDM) have the same mean. Based on literature search, the true mean birthweight for infants whose mothers with GDM is estimated 3,800 grams (± 250 grams). The investigator wants 90% power to detect the differences. A two-tails test conducted at the 0.05 level of significance will be used. What sample size is needed for this study? if the power is changed to 80%, what sample size is then needed?

In a random sample of 39 criminals convicted of a certain​ crime, it was determined that the mean length of sentencing was 57 ​months, with a standard deviation of 7 months. Construct a 95​% confidence interval for the mean length of sentencing for this crime.

the 95​% confidence interval is ​(?,?)

A bakery would like you to recommend how many loaves of its famous marble rye bread to bake at the beginning of the day. Each loaf costs the bakery $2.00 and can be sold for $7.00. Leftover loaves at the end of each day are donated to charity. Research has shown that the probabilities for demands of 25, 50, and 75 loaves are 35%, 20%, and 45%, respectively. Make a recommendation for the bakery to bake 25, 50, or 75 loaves each morning.

Find the expected monetary value when baking 25 loaves.

Find the expected monetary value when baking 50 loaves.

Find the expected monetary value when baking 75 loaves.

In this problem, assume that the distribution of differences is approximately normal. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more "conservative" answer. At five weather stations on Trail Ridge Road in Rocky Mountain National Park, the peak wind gusts (in miles per hour) for January and April are recorded below. Weather Station 1 2 3 4 5 January 139 124 128 64 78 April 108 115 100 88 61 Does this information indicate that the peak wind gusts are higher in January than in April? Use α = 0.01. (Let d = January − April.) (a) What is the level of significance? State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or two-tailed test? H0: μd = 0; H1: μd ≠ 0; two-tailed H0: μd = 0; H1: μd < 0; left-tailed H0: μd > 0; H1: μd = 0; right-tailed H0: μd = 0; H1: μd > 0; right-tailed (b) What sampling distribution will you use? What assumptions are you making? The Student's t. We assume that d has an approximately uniform distribution. The Student's t. We assume that d has an approximately normal distribution. The standard normal. We assume that d has an approximately uniform distribution. The standard normal. We assume that d has an approximately normal distribution. What is the value of the sample test statistic? (Round your answer to three decimal places.) (c) Find (or estimate) the P-value. P-value > 0.250 0.125 < P-value < 0.250 0.050 < P-value < 0.125 0.025 < P-value < 0.050 0.005 < P-value < 0.025 P-value < 0.005 Sketch the sampling distribution and show the area corresponding to the P-value. WebAssign Plot WebAssign Plot WebAssign Plot WebAssign Plot (d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level α? At the α = 0.01 level, we fail to reject the null hypothesis and conclude the data are statistically significant. At the α = 0.01 level, we reject the null hypothesis and conclude the data are not statistically significant. At the α = 0.01 level, we fail to reject the null hypothesis and conclude the data are not statistically significant. At the α = 0.01 level, we reject the null hypothesis and conclude the data are statistically significant. (e) State your conclusion in the context of the application. Reject the null hypothesis, there is insufficient evidence to claim average peak wind gusts are higher in January. Fail to reject the null hypothesis, there is insufficient evidence to claim average peak wind gusts are higher in January. Reject the null hypothesis, there is sufficient evidence to claim average peak wind gusts are higher in January. Fail to reject the null hypothesis, there is sufficient evidence to claim average peak wind gusts are higher in January.

Determine the sample size n needed to construct a 99​% confidence interval to estimate the population proportion when p overbar =0.68 and the margin of error equals 5​%.

n=_______ ​(Round up to the nearest​ integer.)

____________________________________________________________________________________________________________________________

Determine the sample size n needed to construct a 99​% confidence interval to estimate the population mean for the following margins of error when σ=87. ​a) 25 ​b) 40 ​c) 50

“Countries that have single member district elections will have fewer political parties than

countries that have proportional representation elections.”

a. In this hypothesis, state the independent variable, and give examples of two values

that it can take on.

b. State the dependent variable, and give two values that it can take on.

c. Propose one intervening variable that could complete the causal path between the

independent variable and the dependent variable. Explain how it might play this role.

d. Harder. Can you think of a possible confounding variable that might explain the

relationship? Explain how it might play this role.

In BUSINESS, why binary integer programming (BIP) is useful? Thanks!

In this problem, assume that the distribution of differences is approximately normal. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more "conservative" answer. Is fishing better from a boat or from the shore? Pyramid Lake is located on the Paiute Indian Reservation in Nevada. Presidents, movie stars, and people who just want to catch fish go to Pyramid Lake for really large cutthroat trout. Let row B represent hours per fish caught fishing from the shore, and let row A represent hours per fish caught using a boat. The following data are paired by month from October through April. Oct Nov Dec Jan Feb March April B: Shore 1.6 1.8 2.0 3.2 3.9 3.6 3.3 A: Boat 1.5 1.4 1.5 2.2 3.3 3.0 3.8 Use a 1% level of significance to test if there is a difference in the population mean hours per fish caught using a boat compared with fishing from the shore. (Let d = B − A.) (a) What is the level of significance? State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or two-tailed test? H0: μd ≠ 0; H1: μd = 0; two-tailed H0: μd = 0; H1: μd ≠ 0; two-tailed H0: μd = 0; H1: μd > 0; right-tailed H0: μd = 0; H1: μd < 0; left-tailed (b) What sampling distribution will you use? What assumptions are you making? The Student's t. We assume that d has an approximately uniform distribution. The Student's t. We assume that d has an approximately normal distribution. The standard normal. We assume that d has an approximately normal distribution. The standard normal. We assume that d has an approximately uniform distribution. What is the value of the sample test statistic? (Round your answer to three decimal places.) (c) Find (or estimate) the P-value. P-value > 0.500 0.250 < P-value < 0.500 0.100 < P-value < 0.250 0.050 < P-value < 0.100 0.010 < P-value < 0.050 P-value < 0.010 Sketch the sampling distribution and show the area corresponding to the P-value. Maple Generated Plot Maple Generated Plot Maple Generated Plot Maple Generated Plot (d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level α? At the α = 0.01 level, we fail to reject the null hypothesis and conclude the data are statistically significant. At the α = 0.01 level, we reject the null hypothesis and conclude the data are statistically significant. At the α = 0.01 level, we reject the null hypothesis and conclude the data are not statistically significant. At the α = 0.01 level, we fail to reject the null hypothesis and conclude the data are not statistically significant. (e) State your conclusion in the context of the application. Fail to reject the null hypothesis, there is sufficient evidence to claim a difference in population mean hours per fish between boat fishing and shore fishing. Reject the null hypothesis, there is sufficient evidence to claim a difference in population mean hours per fish between boat fishing and shore fishing. Reject the null hypothesis, there is insufficient evidence to claim a difference in population mean hours per fish between boat fishing and shore fishing. Fail to reject the null hypothesis, there is insufficient evidence to claim a difference in population mean hours per fish between boat fishing and shore fishing.

(I need your Reference URL LINK, please)

( i need Unique answer, don't copy and paste, please) (dont' use handwriting, please)

Q1. Define the following terms:
A. Contingency table (Introduction to Biostatistics)
B. Chi-square test (Introduction to Biostatistics)
Q2. List the assumptions required to perform a chi-square test? (Introduction to Biostatistics)

( i need Unique answer, don't copy and paste, please) (dont' use handwriting, please)

Suppose a sample of 49 paired differences that have been randomly selected from a normally distributed population of paired differences yields a sample mean d⎯⎯ =4.1d¯ =4.1 of and a sample standard deviation of sd = 6.8.

(a) Calculate a 95 percent confidence interval for µd = µ1 – µ2. Can we be 95 percent confident that the difference between µ1 and µ2 is greater than 0? (Round your answers to 2 decimal places.)

Confidence interval = [ ,  ] ; (Click to select)YesNo

(b) Test the null hypothesis H0: µd = 0 versus the alternative hypothesis Ha: µd ≠ 0 by setting α equal to .10, .05, .01, and .001. How much evidence is there that µd differs from 0? What does this say about how µ1 and µ2 compare? (Round your answer to 3 decimal places.)

(c) The p-value for testing H0: µd < 3 versus Ha: µd > 3 equals .1316. Use the p-value to test these hypotheses with α equal to .10, .05, .01, and .001. How much evidence is there that µd exceeds 3? What does this say about the size of the difference between µ1 and µ2? (Round your answer to 3 decimal places.)

rev: 07_14_2017_QC_CS-93578, 12_08_2018_QC_CS-150993

You wish to test the following claim (Ha) at a significance level of α=0.001.

      Ho:μ=57.4
      Ha:μ>57.4

You believe the population is normally distributed and you know the standard deviation is σ=6.6. You obtain a sample mean of M=59.7 for a sample of size n=72.

What is the critical value for this test? (Report answer accurate to three decimal places.)
critical value =

What is the test statistic for this sample? (Report answer accurate to three decimal places.)
test statistic =

The test statistic is...

in the critical region

not in the critical region

This test statistic leads to a decision to...

reject the null

accept the null

fail to reject the null

As such, the final conclusion is that...

There is sufficient evidence to warrant rejection of the claim that the population mean is greater than 57.4.

There is not sufficient evidence to warrant rejection of the claim that the population mean is greater than 57.4.

The sample data support the claim that the population mean is greater than 57.4.

There is not sufficient sample evidence to support the claim that the population mean is greater than 57.4.