Large Sample Proportion Problem.  Surveys were conducted in multiple countries and respondents were asked if they felt political news was reported fairly. The data for the United States is that out of 1,000 sampled, 470 indicated yes, they felt political news was reported fairly. Suppose we want to determine if the proportion for the U.S. is below .50 for an alpha level of .05.

What is conclusion of my test?

Group of answer choices

I would reject Ho: P=.5 because the test statistic is less than -1.645

I would fail to reject Ho: P=.5 because the p-value is greater than .05

I would reject Ho: P=.5 because the test statistic is greater than 1.645

I would fail to reject Ho: P=.5 because the test statistic is greater than -1.96

Test whether there is a difference in the means of the two lists of numbers. Pay attention to the variances. Answer the following questions. Use alpha = 0.05.

Set 1: 44, 11, 27, 30, 27, 30, 17, 12 , 17, 9, 14, 24, 13, 9, 13, 15, 13, 15, 15, 23, 53, 33, 10, 6, 17, 14, 5, 25, 18, 23, 13, 12, 8, 17, 12, 36, 10, 4, 6, 32

Set 2: 20, 12, 23, 12, 25, 11, 21, 13, 25, 24, 36, 22, 2, 24, 15, 12, 22, 24, 17, 8, 13, 21, 18, 24, 27, 14, 12, 18, 20, 8, 10, 4, 14, 7, 26, 27, 12, 22, 10, 10

Is this a one or two-tailed test?

T=?

P=?

Decision (fail to reject Ho or Reject)?

Thank you so much for helping!

A corrections researcher is examining prison health care coasts and wants to determine how long inmates survive once diagnosed with a particular form of cancer. Using data collected from a group of 45 patients with the disease, she observes an average survival time (time until death) of 32 months with a standard deviation of 9 months. Using a 95 percent level of confidence, estimate the population mean survival time. What would the 99% confidence interval be?

(6 pts total; 2pt each CI, 1pt each interpretation)

1. 95% Confidence Interval:

2. Interpretation:

3. 99% Confidence Interval:

4. Interpretation:

You want to see graphically the effect of changing the standard deviation of a Normal distribution. Let μ = 100 for both distributions, but let σ = 10 for one and σ = 16 for the other distribution. Recall that for each distribution the first value should be 3σ below the mean of 100, and the last value should be 3σ above the mean of 100. When MINITAB creates the X values for you, for both distributions this time set the data IN STEPS OF 2. Overlay the two density functions on the same graph (in MINITAB), and paste in the box below. [PLEASE SHOW STEPS ON HOW TO DO THIS IN MINITAB]

The Accountability ratings for sixteen (16) school districts in the Delta Region of Mississippi on a 500 point rating scale are as follows: 102, 225, 222, 379, 208, 120, 250, 449, 229, 182, 214, 141, 150, 309, 256, & 263 Determine the following: a. Third Decile b. Fourth Decile c. Fifth Decile d. Sixth Decile e. Seventh Decile f. Eighth Decile g. Ninth Decile

7.74 Beverage consumption. The results in the previous exercise were based on two national surveys with a very large number of individuals. Here is a study that also looked at beverage consumption, but the sample sizes were much smaller. One part of this study compared 20 children who were 7 to 10 years old with 5 37 to 19.9 oz. The authors state that the difference is statistically significant with P<0.01. information you would need to compute a confidence interval for the increase, and outline the procedure that you would use for the computations. Do you think that a confidence interval would provide useful additional information? Explain why or why not. children who were 11 to 13. day, while the older ones averaged 14.5 oz. The standard deviations were 10.7 oz and 8.2 oz, respectively. The younger children consumed an average of 8.2 oz of sweetened drinks per (a) Do you think that it is reasonable to assume that these data are Normally distributed? Explain why or why not. (Hint: Think about the 68–95–99.7 rule.) (b) Using the methods in this section, test the null hypothesis that the two groups of children consume equal amounts of sweetened drinks versus the two-sided alternative. Report all details of the significance-testing procedure with your conclusion. (c) Give a 95% confidence interval for the difference in means. (d) Do you think that the analyses performed in parts (b) and (c) are appropriate for these data? Explain why or why not. (e) The children in this study were all participants in an intervention study at the Cornell Summer Day Camp at Cornell University. To what extent do you think that these results apply to other groups of children?

In a study of the length of time it takes to earn an associate’s degree, a random sample of 41 students had a mean of 2.8 years. Assume that the population standard deviation is 0.9 years. You wish to construct a 99% confidence interval for the mean time it takes to earn an associate's degree. Use this information to answer the next 5 questions. (Be sure to use the correct distribution.)

What is the confidence interval? Round to 2 decimal places.

If applicable, what are the degrees of freedom? (Type NA if not applicable.)

What is the critical value?

What is the point estimate?

What is the margin of error? Round to 2 decimal places.

7.78 Does ad placement matter? Corporate advertising tries to enhance the image of the corporation. A study compared two ads from two sources, the Wall Street Journal and the National Enquirer. Subjects were asked to pretend that their company was considering a major investment in Performax, the fictitious sportswear firm in the ads. Each subject was asked to respond to the question “How trustworthy was the source in the sportswear company ad for Performax?” on a 7-point scale. Higher values indicated more trustworthiness. 38 Here is a summary of the results: Ad source Wall Street Journal National Enquirer n x ̄ s 66 4.77 1.50 61 2.43 1.64 (a) Compare the two sources of ads using a t test. Be sure to state your null and alternative hypotheses, the test statistic with degrees of freedom, the P-value, and your conclusion. (b) Give a 95% confidence interval for the difference. (c) Write a short paragraph summarizing the results of your analyses.

Why do you think researchers use samples?

Why do you think we also use null and alternative (research) hypotheses?

Refer to the traffic congestion cost table as the primary source of your observations, and do the followings;

1.     Summarize the cost by calculating the mean and standard deviation for each region

2.     Calculate the Standard deviation for all five regions ONLY TYPED HARD COPY IS ACCEPTED

3.     Use a bar graph for this data set and show the five averages on the graph

4.     List all the averages and standard deviations of five regions for comparison

1) Use Excel to develop a regression model for the Consumer Food Database (using the “Excel Databases.xls” file on Blackboard) to predict Annual Food Spending by Annual Household Income for those living in the Metro area only.   

Suppose a household in the metro area has an annual income of $60,000. Predict how much they spend on food per year. Write your answer as a number (do not include the $ sign or comma) and round to 2 decimal places.

Question 1

An office will increase salary to its top 8% employees on the basis of a performance score the office created for each employee. The performance score is approximately normal with mean 82.5 and standard deviation 9.25.

How high must an employee score in order to qualify for increase in the salary?

Group of answer choices

87.50

85.75

95.50

82.50

Question 2

The performance score of employees in an office is approximately normal with mean 82.5 and standard deviation 9.25.

What is the third quartile (Q3) of the performance score of the employees?

(Hints: Recall that the third quartile is a score with 75% data values below it and 25% data values above it)

Group of answer choices

9.25

88.74

82.50

76.26

Question 3

Running times for 400 meters are Normally distributed for young men between 18 and 30 years of age with a mean of 93 seconds and a standard deviation of 16 seconds. How fast does a man have to run to be in the top 5% of runners (quickest runner)?

Group of answer choices

119.32 seconds

66.68 seconds

109.32 seconds

93.68 seconds

Question 4

The typical college freshman spends an average (mean) of 150 minutes per day with a standard deviation of 50 minutes on social media. The distribution of time on social media is known to be Normal.

What is the probability that students will spend between 140 minutes and 200 minutes on social media?

Group of answer choices

0.22

0.82

0.62

0.42

Question 5

A company produces packets of soap powder labeled “Giant Size 32 Ounces.” The actual weight of soap powder in such a box has a Normal distribution with a mean of 33 oz and a standard deviation of 0.7 oz. The company says a box of soap is considered underweight if it weighs less than 32 oz.

What is the probability that a box of soap is underweight (i.e., weigh less than 32 oz)?

Group of answer choices

0.7066

0.0766

0.7

0.5066

In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal distribution to estimate the requested probabilities. What's your favorite ice cream flavor? For people who buy ice cream, the all-time favorite is still vanilla. About 20% of ice cream sales are vanilla. Chocolate accounts for only 10% of ice cream sales. Suppose that 175 customers go to a grocery store in Cheyenne, Wyoming, today to buy ice cream. (Round your answers to four decimal places.)

(a) What is the probability that 50 or more will buy vanilla?

(b) What is the probability that 12 or more will buy chocolate?

(c) A customer who buys ice cream is not limited to one container or one flavor. What is the probability that someone who is buying ice cream will buy chocolate or vanilla? Hint: Chocolate flavor and vanilla flavor are not mutually exclusive events. Assume that the choice to buy one flavor is independent of the choice to buy another flavor. Then use the multiplication rule for independent events, together with the addition rule for events that are not mutually exclusive, to compute the requested probability.

(d) What is the probability that between 50 and 60 customers will buy chocolate or vanilla ice cream? Hint: Use the probability of success computed in part (c).

The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line, yˆ=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.

Price in Dollars 31 32 34 38 48 Number of Bids 2 4 5 7 10

Step 3 of 6 : Substitute the values you found in steps 1 and 2 into the equation for the regression line to find the estimated linear model. According to this model, if the value of the independent variable is increased by one unit, then find the change in the dependent variable yˆ.

4.Determine the value of the coefficient of determination

5.Determine if the statement True or False."Not the points predicted by the linear model found on the same line.True or false

6.Determine the value of the dependent variable y at x=0 =

A simple random sample from a population with a normal distribution of 109 body temperatures has x=98.10 degrees F and s=0.67° F.

Construct a 99​% confidence interval estimate of the standard deviation of body temperature of all healthy humans.