A political scientist is interested in the effectiveness of a political ad about a particular issue. The scientist randomly asks 18 individuals walking by to see the ad and then take a quiz on the issue. The general public that knows little to nothing about the issue, on average, scores 50 on the quiz. The individuals that saw the ad scored an average of 49.61 with a standard deviation of 5.02. What can the political scientist conclude with an α of 0.01?

a) What is the appropriate test statistic?
---Select--- na z-test one-sample t-test independent-samples t-test related-samples t-test

b)
Population:
---Select--- the political ad general public the particular issue individuals walking by the ad
Sample:
---Select--- the political ad general public the particular issue individuals walking by the ad

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.)
critical value =  ; test statistic =
Decision:  ---Select--- Reject H0 Fail to reject H0

d) If appropriate, compute the CI. If not appropriate, input "na" for both spaces below.
[  ,  ]

e) 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

f) Make an interpretation based on the results.

Individuals that watched the political ad scored significantly higher on the quiz than the general public.Individuals that watched the political ad scored significantly lower on the quiz than the general public.    Individuals that watched the political ad did not score significantly different on the quiz than the general public.

True or False? A hypothesis test is conducted at to test whether the population correlation coefficient is zero. If the sample size is 25 and the sample correlation coefficient is 0.6, then the critical values of the student t that define the upper and lower tail rejection areas are 2.069 and -2.069, respectively.

The developers of a new online game have determined from preliminary testing that the scores of players on the first level of the game can be modelled satisfactorily by a Normal distribution with a mean of 185 points and a standard deviation of 28 points. They would like to vary the difficulty of the second level in this game, depending on the player’s score in the first level. (a) The developers have decided to provide different versions of the second level for each of the following groups: (i) those whose score on the first level is in the lowest 25% of scores ii) those whose score on the first level is in the middle 50% of scores (iii) those whose score on the first level is in the highest 25% of scores. Use the information given above to determine the cut-off scores for these groups. (You may round each of your answers to the nearest whole number.) (b) In the second level of the game, the developers have also decided to give players an opportunity to qualify for a bonus round. Their stated aim is that players from group (i) should have 75% chance of qualifying for the bonus round, players from group (ii) should have 55% chance of qualifying for the bonus round and that players from group (iii) should have 30% chance of qualifying for this round. Let ?, ? and ? respectively denote the events that a player’s score on the first level was in the lowest 25% of scores, the middle 50% of scores and the highest 25% of scores, and let ? denote the event that the player qualifies for the bonus round. Use event notation to express the developers’ aim as a set of conditional probabilities. (c) Based on the developers’ stated aim, find the total probability that a randomly chosen player will qualify for the bonus round. (d) Given that a player has qualified for the bonus round, what is the probability that the player’s score on the first level was in the middle 50% of scores for that level? (e) Given that a player has not qualified for the bonus round, what is the probability that the player’s score on the first level was in the lowest 25% of scores for that level?

The table below summarizes baseline characteristics of patients participating in a clinical trial. a) Are there any statistically significant differences in baseline characteristics between treatment groups? Justify your answer.

The probability is0.45 that a traffic fatality involves an intoxicated or​ alcohol-impaired driver or nonoccupant. In

seven traffic​ fatalities, find the probability that the​ number, Y, which involve an intoxicated or​ alcohol-impaired driver or nonoccupant is

a. exactly​ three; at least​ three; at most three.

b. between two and four​, inclusive.

c. Find and interpret the mean of the random variable Y.

d. Obtain the standard deviation of Y.

You are conducting a study to see if the proportion of voters who prefer the Democratic candidate is significantly larger than 54% at a level of significance of αα = 0.01. According to your sample, 38 out of 61 potential voters prefer the Democratic candidate.

1. For this study, we should use Select an answer t-test for a population mean z-test for a population proportion
2. The null and alternative hypotheses would be:
   Ho: ? p μ  ? = ≠ < >   (please enter a decimal)   
   H₁: ? p μ  ? = > < ≠   (Please enter a decimal)

3. The test statistic ? t z  =  (please show your answer to 3 decimal places.)
4. The p-value =  (Please show your answer to 4 decimal places.)
5. The p-value is ? > ≤  αα
6. Based on this, we should Select an answer reject accept fail to reject  the null hypothesis.
7. Thus, the final conclusion is that ...
   • The data suggest the population proportion is not significantly larger than 54% at αα = 0.01, so there is not sufficient evidence to conclude that the proportion of voters who prefer the Democratic candidate is larger than 54%.
   • The data suggest the populaton proportion is significantly larger than 54% at αα = 0.01, so there is sufficient evidence to conclude that the proportion of voters who prefer the Democratic candidate is larger than 54%
   • The data suggest the population proportion is not significantly larger than 54% at αα = 0.01, so there is sufficient evidence to conclude that the proportion of voters who prefer the Democratic candidate is equal to 54%.
8. Interpret the p-value in the context of the study.
   • There is a 9.68% chance that more than 54% of all voters prefer the Democratic candidate.
   • If the sample proportion of voters who prefer the Democratic candidate is 62% and if another 61 voters are surveyed then there would be a 9.68% chance of concluding that more than 54% of all voters surveyed prefer the Democratic candidate.
   • There is a 9.68% chance of a Type I error.
   • If the population proportion of voters who prefer the Democratic candidate is 54% and if another 61 voters are surveyed then there would be a 9.68% chance that more than 62% of the 61 voters surveyed prefer the Democratic candidate.
9. Interpret the level of significance in the context of the study.
   • If the proportion of voters who prefer the Democratic candidate is larger than 54% and if another 61 voters are surveyed then there would be a 1% chance that we would end up falsely concluding that the proportion of voters who prefer the Democratic candidate is equal to 54%.
   • If the population proportion of voters who prefer the Democratic candidate is 54% and if another 61 voters are surveyed then there would be a 1% chance that we would end up falsely concluding that the proportion of voters who prefer the Democratic candidate is larger than 54%
   • There is a 1% chance that the earth is flat and we never actually sent a man to the moon.
   • There is a 1% chance that the proportion of voters who prefer the Democratic candidate is larger than 54%.

In an introductory statistics class, there are 18 male and 22 female students. Two students are randomly selected (without replacement).

(a) Find the probability that the first is female

(b) Find the probability that the first is female and the second is male.

(c) Find the probability that at least one is female

---------------

I know that this question has to use the counting method, but i got confuse with how to start because i have to now find the probability of FIRST being a female, etc. Please provide workings with explanations alongside. Thank you in advance!

A scatterplot is the best way to show the mode of a categorical variable. (True/False)

An observational study with a convenience sample provides the strongest evidence that a predictor causes an outcome. (True/False)

Given a normal distribution, find the percentage of observed records that will be within 1.5 standard deviations (1.5 standard deviation to the left AND right of the mean). Show calculations and/or R code used to find your answer.

1. A composites manufacturer is having serious problems with porosity in their parts. A Quality Engineer samples 300 parts and finds 58 defective.

1. Test the hypothesis that defective rate (proportion defective) exceeds 15%. Test at a = 0.05.

What is the parameter of interest?   What assumptions are made? Show mathematical evidence to support assumption.

i. Write the null and alternative hypotheses.

ii. Calculate the test statistic.

iii. Determine the reject region. Find the p-value. Show normal graph including reject region and test statistic.

iv. Make a decision and write a thorough interpretation in context of the problem.

v. If in reality the true proportion defective is 12%, what type of error, if any, occurred?

2. Compute the power of the test if the true defective rate is 0.18.
3. Suppose that you wanted to reject the null hypothesis with probability at least 0.9 if true defective rate p = .18. What sample size should be used?
4. Construct a 95% Confidence Interval for p, the true proportion defective.

( PLEASE SHOW ALL YOUR WORK). I

MPORTANT NOTE: Make sure you do the following: -State Ho and Ha using notation for each hypothesis test conducted. -Use α= 0.05 for all hypothesis tests conducted. -Explain all results obtained for both hypothesis tests and confidence intervals.

You will need your ticker code (company abbreviation) for stock prices for this question. Use your ticker code to obtain the closing prices for the following two time periods to obtain two data sets:

March 2, 2019 to March 16, 2019

Data set A

February 16, 2019 to February 28, 2019

Data set B

Take the closing prices from data set B and add 0.5 to each one of them. Treat data sets A and B as hypothetical sample level data on the weights of newborns whose parents smoke cigarettes (data set A), and those whose parents do not (data set B).

a) Conduct a hypothesis test to compare the variances between the two data sets.

b) Conduct a hypothesis to compare the means between the two data sets. Selecting the assumption of equal variance or unequal variance for the calculations should be based on the results of the previous test.

c) Calculate a 95% confidence interval for the difference between means

A school psychologist believes that a popular new hypnosis technique increases depression. The psychologist collects a sample of 25 students and gives them the hypnosis once a week for two months. Afterwards the students fill out a depression inventory in which their average score was 53.88. Normal individuals in the population have a depression inventory average of 50 with a variance of 100.00. What can the psychologist conclude with α = 0.01?

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

b)
Population:
---Select--- students receiving hypnosis ,normal individuals, two months ,new hypnosis ,technique depression
Sample:
---Select--- students receiving hypnosis ,normal individuals ,two months, new hypnosis ,technique depression

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.)
critical value = ; test statistic =  
Decision: ---Select--- Reject H0 or Fail to reject H0

d) If appropriate, compute the CI. If not appropriate, input "na" for both spaces below.
[ , ]

e) Compute the corresponding effect size(s) and indicate magnitude(s).
If not appropriate, input and 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

f) Make an interpretation based on the results.

A.The depression of students that underwent hypnosis is significantly higher than the population.

B.The depression of students that underwent hypnosis is significantly lower than the population.    

C.The depression of students that underwent hypnosis is not significantly different than the population.

True or False

1. T F   Six Sigma relates to a 3.4 DPMO.

2. T F Six Sigma can not be applied to service companies.

3. T F   Walter Shewhart stated that, “A phenomenon is said to be in statistical control when, through the use of past experience, we can say that our product is within the specification limits.”

4. T F   Variation exists in every process.

5. T F   Potential sources of variation include methods, manpower, material, and equipment.

6. T F   The voice of the customer is usually expressed on the control chart as control limits.

7. T F   Quality begins with control and inspection.

8. T F   Product quality is determined during the manufacturing of the product.

9. T F   Most companies operate at a 3 to 4 sigma level.

10. T F   The project charter serves as contract between project team and sponsor.

11. T F   Once the project charter is develop and completed, it should not be changed in order to avoid confusion.

A genetic experiment involving peas yielded one sample of offspring consisting of 416 green peas and 144 yellow peas. Use a 0.05 significance level to test the claim that under the same circumstances, 23% of offspring peas will be yellow. Identify the null hypothesis, alternative hypothesis, test statistic, P value, conclusion about the null hypothesis, and the final conclusion that addresses the The original claim. Use the P value method and the normal distribution as an approximation to the binomial distribution.

1. One of the most important measures of the quality of service provided by any firm is the speed with which it responds to customer complaints. Comcast, a U.S. global telecommunications conglomerate, wants to greatly improve its customer satisfaction. Comcast states the desired mean call time involving customer complaints is 12 minutes (including wait time). Assume the standard deviation is known to be 0.15 minutes. A sample of 70 customer calls yields a mean time of 12.14 minutes. This sample will be used to obtain a 99% confidence interval for the mean time of a customer complaint call. Round final answers to two decimal places. Solutions only.

(A) The critical value to use in obtaining the confidence interval is.

(B) The confidence interval goes from to.

(C) True, False, or Uncertain: The confidence interval indicates that Comcast is not meeting its goal.

(D) True, False, or Uncertain: The confidence interval is valid only if the length of calls are normally distributed

(E) Suppose the manager had decided to estimate the mean call time to within 0.03 minutes with 99% confidence. Then the sample size would be?