a simple random sample of 225 college students was taken in order to estimate the proportion of college students that agrees with the "no teacher left alone act". of those surveyed, 142 agreed with the law. construct the 95% confidence interval estimate of the proportion of all college students that agrees with this law

Sample
80
80
80
81
81
64
65
65
66
67
67
67
71
71
72
72
72
72
73
73
73
90
91
93
96

Today, the professor claims the mean student performance on his midterm has significantly improved from last year. Last year, the mean midterm score for all of his students was 70. The professor uses a random sample of 25 student’s midterm scores (column 2). Use a hypothesis test (t-test) to test the professors claim using a 5% significance level.

1) What is the value of the test statistic?

2) What is the critical value from the t-table?

3) What is the p-value?

4) Can the professor conclude this year’s mean midterm score has improved? Explain!

While regression analysis is a useful tool for making budgeting predictions, learning how to become proficient in regression analysis is beyond the scope. But, knowing what regression analysis can do for the budgeting process is important. Write a short paragraph, or two, explaining what you feel regression analysis can provide during the budgeting process.

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.

In a random sample of 60 professional actors, it was found that 35 were extroverts.

(a) Let p represent the proportion of all actors who are extroverts. Find a point estimate for p. (Round your answer to four decimal places.)


(b) Find a 95% confidence interval for p. (Round your answers to two decimal places.)

Give a brief interpretation of the meaning of the confidence interval you have found.

We are 95% confident that the true proportion of all actors who are extroverts falls outside of 0.46 and 0.71.We are 5% confident that the true proportion of all actors who are extroverts falls between 0.46 and 0.71.    We are 5% confident that the true proportion of all actors who are extroverts falls above 0.46 and 0.71.We are 95% confident that the proportion of all actors who are extroverts falls between 0.46 and 0.71.

(c) Do you think the conditions np is greater than or equal to 15 and n*(1 - p) is greater than or euqal to 15 are satisfied in this problem? Explain why this would be an important consideration.

A No, the conditions are not satisfied. This is important because it allows us to say that the sampling distribution of p̂ is approximately normal.

B Yes, the conditions are satisfied. This is important because it allows us to say that the sampling distribution of p̂ is approximately binomial.

C No, the conditions are not satisfied. This is important because it allows us to say that the sampling distribution of p̂ is skewed right.

D Yes, the conditions are satisfied. This is important because it allows us to say that the sampling distribution of p̂ is approximately normal.

Let A,B, and C be independent random variables, uniformly distributed over [0,9] [0,6],and [0,8] respectively. What is the probability that both roots of the equation Ax2+Bx+C=0are real?

please answer all parts of question, thank you so much

12. Identify the correct statements. Fix the incorrect ones.

a. A sampling distribution describes the distribution of data values.

b. A sampling distribution shows the behavior of a sampling process over many samples.

c. The probability distribution of a parameter is called a sampling distribution.

d. Sampling distributions describe the values of a data summary for many samples.

14. 14. Why is random sampling important?

18. A large university wants to send an exit survey to a SRS of 500 of its 3,827 graduating seniors. One question is, “Would you recommend to others that they should attend the university?” The response choices are: not sure, not likely, likely, definitely, most definitely. Describe how you would (in theory) use repeated sampling to obtain the sampling distribution of the sample proportion who would “definitely” or “most definitely” recommend the university to others.

It is generally accepted that patients grow anxious when a person with a white coat and stethoscope walks into an examining room; i.e., patients have white coat hypertension. A family practitioner hypothesizes the opposite effect. To test this, the practitioner has colleagues from the practice randomly visit patients in a white coat or non-white sport coat, and measure their blood pressure. What can the practitioner conclude with an α of 0.05? Below are the systolic blood pressures of the patients.

a) What is the appropriate test statistic?
---Select--- na z-test One-Sample t-test Independent-Samples t-test Related-Samples t-test

b)
Condition 1:
---Select--- examining room white coat hypertension non-white coat white coat blood pressure
Condition 2:
---Select--- examining room white coat hypertension non-white coat white coat blood pressure

c) Compute the appropriate test statistic(s) to make a decision about H₀.
(Hint: Make sure to write down the null and alternative hypotheses to help solve the problem.)
p-value =  ; Decision:  ---Select--- Reject H0 Fail to reject H0

d) compute the corresponding effect size(s) and indicate magnitude(s).
If not appropriate, input and/or select "na" below.
d =  ;   ---Select--- na trivial effect small effect medium effect large effect
r² =  ;   ---Select--- na trivial effect small effect medium effect large effect

e) Make an interpretation based on the results.

The systolic blood pressure for patients that where visited by a practitioner with a white coat was significantly higher from patients that were visited by a practitioner in a non-white sport coat.

The systolic blood pressure for patients that where visited by a practitioner with a white coat was significantly lower from patients that were visited by a practitioner in a non-white sport coat.    

The systolic blood pressure for patients that where visited by a practitioner with a white coat did not significantly differ from patients that were visited by a practitioner in a non-white sport coat.

1. Suppose it is claimed that the mean weight of a bag of the same brand of candies is 0.13 ounces. You wish to show that it is not 0.13 ounces and wish to test the claim at α = 0.01 level. You collected a sample of 16 small bags of the same brand of candies. The weight of each bag was then recorded. The mean weight was two ounces with a standard deviation of 0.12 ounces. Assume that the population distribution of bag weights is normal with a known population standard deviation of 0.1 ounce.
   1. State the null and alternate hypotheses clearly.
   2. Conduct the hypothesis test based on the test statistic and critical value(s). Clearly indicate each.
   3. What is the p-value? Use the p-value to conduct the same test
   4. Report your conclusion in words, in the context of the problem.

*Work on excel*

1. You’ve been assigned to a special quality control task force in your firm to assess the performance reliability of your firm’s three regional factories (Factory A, Factory B, and Factory C) where desk lamps are manufactured.

Your task force collected the following background information (where A = Factory A; B = Factory B,
C = Factory C, D = defective).

If a randomly selected lamp is defective,

            a. What is the probability that the lamp was manufactured in Factory A?

            b. What is the probability that the lamp was manufactured in Factory B?

            c. What is the probability that the lamp was manufactured in Factory C?

A software engineer is creating a new computer software program. She wants to make sure that the crash rate is extremely low so that users would give high satisfaction ratings. In a sample of 780 users, 39 of them had their computers crash during the 1-week trial period.

(a)

What is the sample size?

What is p̂?

(b)

What is the 95% confidence interval for p̂? (Use a table or technology. Round your answers to three decimal places.)

The table below summarizes the mean psychological distress score of persons who are married to or cohabiting with a romantic partner and those who are not. Psychological distress is a scale of feelings of depression and anxiety, ranging from 0 to 24, where higher scores indicate more distress. In answering these questions, show all of your work.

1. Construct a 95% confidence interval for psychological distress for respondents who are married to or cohabiting with a romantic partner.

2. Construct a 95% confidence interval for psychological distress for respondents who are not in a romantic relationship.

3. Compare the relative width of these two confidence intervals. Why do they differ?

4. Interpret one of these confidence intervals

5. Construct a 68% interval for respondents who are married to or cohabiting with a romantic partner.

Confidence intervals, effect sizes, and Valentine’s Day spending: According to the Nielsen Company, Americans spend $345 million on chocolate during the week of Valentine’s Day. Let’s assume that we know the average married person spends $45, with a population standard deviation of $16. In February 2009, the U.S. economy was in the throes of a recession. Comparing data for Valentine’s Day spending in 2009 with what is generally expected might give us some indication of the attitudes during the recession. a. Compute the 95% confidence interval for a sample of 18 married people who spent an average of $38. b. How does the 95% confidence interval change if the sample mean is based on 180 people? c. If you were testing a hypothesis that things had changed under the financial circumstances of 2009 as compared to previous years, what conclusion would you draw in part (a) versus part (b)? d. Compute the effect size based on these data and describe the size of the effect.

A certain data distribution has a mean of 18 and a standard deviation of 3

Wha, is the value would have a Z-score of -3.2?

Assuming that the distribution is normal, use the Empirical Rule to determine what proportion of this distribution would be found to be between 15 and 24

Assuming that the distribution is normal, use the Empirical Rule to determine what proportion of his distribution would be found to be between 12 and 15

Now imagine that this distribution is NOT guaranteed to be normally distributed. What would be the minimum proportion of this distribution that might be found between 13.5 and 22.5?

In one year, there were 17,737 fatal injuries in California, and 11,149 of them were unintentional. Using the data from this year, construct a 98% confidence interval estimate of the percentage of California fatal injuries that are unintentional. Interpret the interval as well.