Q2. Outline the differences between paired and unpaired t-test with examples. Compare z-test with t-test and explain how and why a t-distribution is different from a z-distribution.
Q: A professor of statistics noticed that the marks in his course are normally distributed. He has also…
A: μ1=0.78, σ1=0.15μ2=0.74, σ2=0.13
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A: we use the two-tailed difference in mean values; null, Ho: u1 = u2 alternate, H1: μ1 ≠ u2
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A: woman : μ2 = 65323σ2 = 13274X2 = 107000Z = ?
Q: (a) What are the null hypothesis H, and the alternative hypothesis H, that should be used for the…
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A: given data : 46,41,50,52,47,63,47,46,49,46,53,52
Q: Help!!
A: (a) Given: μ=374, σ=64, n=5 The corresponding z-value needed to be computed is: The probability…
Q: A researcher is going to perform a left-tailed hypothesis test. The test statistic will follow a…
A: The information extracted from the problem are,The test is left tailed.Test statistic, z = -1.743
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Q: When would you use a factorial ANOVA and what are the three F values that are calculated?
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Q: Your friend Chung took the entrance exam for Company C along with a group of four other of his…
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A: ANOVA is a study which is non parametric. ANOVA stands for "Variance Analysis" and is used to…
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A: The following information has been provided: For Males : Sample Mean 1 (Xˉ1)(\bar X_1)= 282282…
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A: We have given statement about the F -test
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A: Given information: The output of Friedman test is given.
Q: (b) Prove that for Cauchy's distribution not sample mean but sample median is a consistent estimator…
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Q: (a) Calculate the sampling error at 95% confidence level (b) Construct a 95% confidence interval…
A: Given that Sample size n =25 Sample mean =53 Population standard deviation =5.5 NOTE:- According to…
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A: To reject the null hypothesis the test statistics must be in....
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Q: (a) Give a point estimate of the population mean running time for a 400-meter race. (b) Calculate…
A: here as per guidelines i have calculated 3 subparts , repost for remaining here sample mean = 53…
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A: Solution null hypothesis for one-way ANOVA with k groups is H0 : µ1 = ··· = µk. The alternative…
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Q: 1.1, 14.3 39
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A: Mean()=73Standard deviation()=0.6Sample size(n)=40
Q: Explain the Process of Computing the p-value using the F-statistic?
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A: Givensample size(n)=1100p^=0.37confidence interval=95%
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A: In order to use the unpooled t-test, we need to assume that the two population variances are…
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A: The degrees of freedom is obtained as follows: Df=n-1 =5-1 =4 The critical-value is obtained…
Q: p1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. Ho : Ha =…
A: here test there is a significant difference between the IQs of two group and it is paired data
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A: To test a hypothesis such as caffeine improves memory in the caffeine study: In this case, two…
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- A union of restaurant and foodservice workers would like to estimate the mean hourly wage, u, of foodservice workers in the U.S. this year The mean hourly wage last year was $8.08, and there is good reason to believe that this year's value is different from last year's. The union decides to do a statistical test to see if the value has indeed changed. The union chooses a random sample of this year's wages, computes the mean of the sample to be $7.78, and computes the standard deviation of the sample to be $1.20. Based on this information, complete the parts below. (a) What are the null hypothesis H. and the alternative hypothesis H₁ that should be used for the test? H₂ : O H₁ :0 (b) Suppose that the union decides not to reject the null hypothesis. What sort of error might it be making? (Choose one) ▼ (c) Suppose the true mean hourly wage for foodservice workers in the U.S. this year is $8.08. Fill in the blanks to describe a Type I error. A Type I error would be (Choose one) when, in…What effect does standardizing into z-scores have on the spread (standard deviation) of a variable?Lalli long jumper is a teacher in a crowded school here in the city. He is very interested in long jump and he decided to study the long jump ability of the school's students. He held a long jump competition where all the students at the school took part and he measured the length of the students' jumps. Let us now assume that the length of the jump among the students at the school follows a normal distribution with an average of 4 meters and a standard deviation of 1 meter. Lalli randomly selected 100 participants from the long jump competition and asked them if they enjoyed long jump. 62 respondents said they enjoyed long jump. Lalli used the data to create a 95% confidence interval for the proportion of students who enjoy long jump. What is the lower limit of the safety gap? a.) 0.45 b.) 0.52 c.) 0.58 d.) 0.61 e.) 0.71
- Describe the difference in the conclusions that one could draw from a sample T-test when CLT did NOT kick in, as in qqnorm() did not show a normal distribution for the sample size. What could one do instead of a T-test, and what would their test statistic be?A union of restaurant and foodservice workers would like to estimate the mean hourly wage, mean population , of foodservice workers in the U.S. this year The mean hourly wage last year was $8.08 , and there is good reason to believe that this year's value is greater than last year's.The union decides to do a statistical test to see if the value has indeed increased. The union chooses a random sample of this year's wages, computes the mean of the sample to be $8.45 , and computes the standard deviation of the sample to be $1.20. Based on this information, complete the parts below. (a) What are the null hypothesis and the alternative hypothesis that should be used for the test? (b) Suppose that the union decides not to reject the null hypothesis. What sort of error might it be making? Select one: Type I or Type II (c) Suppose the true mean hourly wage for foodservice workers in the U.S. this year is $8.08 . Fill in the blanks to describe a Type I error.A Type I error would be (Select…Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2. Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.
- How do I apply a normal curve to a sample of test scores. n=50 range=27 min=72 max=99 mean=85.94 median=87 mode=89 standard deviation=5.99 skewness= -.39A research team is working on a project to study the time (in seconds) for high school male runners to finish a 400-meter race. Jimmy, a junior researcher in the team, has randomly selected a sample of 25 male runners from a high school and the time (in seconds) for each of them to complete a 400-meter race was recorded. The sample mean running time was 53 seconds. It is assumed that the running time in a 400-meter race follows a normal distribution with a population standard deviation of 5.5 seconds.(a) Give a point estimate of the population mean running time for a 400-meter race.(b) Calculate the sampling error at 95% confidence level.(c) Construct a 95% confidence interval estimate of the population mean running time for a 400-meter race.How does the sample size affect how close to normal a distribution of either sample means or sample pro-portions will be? What are the means and standard deviations of the distributions in each case?
- An instructor of statistics believes that the mean score of students on the first statistics test is 65 out of 100 marks. He randomly samples 10 statistics student scores and obtains the average scores as 63 with a standard deviation of 5.01. He performs a hypothesis test to know whether the mean score of students is varied from 65 by using a 5% level of significance.A psychology graduate student wants to test the claim that there is a significant difference between the IQs of spouses. To test this claim, she measures the IQs of 9 married couples using a standard IQ test. The results of the IQ tests are listed in the following table. Using a 0.02 level of significance, test the claim that there is a significant difference between the IQs assuming that the population distribution of the paired differences is approximately normal. Let the spouse 1 group be Population 1 and let the spouse 2 group be Population 2. IQs of Married Couples Spouse 122 129 105 103 119 111 127 105 1 Spouse 122 131 107 106 118 122 112 126 108 2 Copy Data Step 3 of 3: Draw a conclusion and interpret the decision. Answer E Tables 国 Keypad Keyboard Shortcuts We fail to reject the null hypothesis and conclude that there is insufficient evidence at a 0.02 level of significance to support the claim that there is a significant difference between the IQs of spouses. We reject the…