Question

In: Math

A researcher wishes to test the effects of excerise on the ability to complete a basic...

A researcher wishes to test the effects of excerise on the ability to complete a basic skills test. He designs a pre-test and post-test to give to each participant. You believe that there was an increase in the scores. You believe the population of the differences is normally distributed, but you do not know the standard deviation. When calculating difference use Post-test minus Pre-test. pre-test post-test 52 60 60 55 44 49 92 94 84 76 55 65 64 58 67 66 53 59 99 99 75 79 77 82 Which of the following are the correct hypotheses? H 0 : μ d ≥ 0 H 0 : μ d ≥ 0 H A : μ d < 0 H A : μ d < 0 (claim) H 0 : μ d ≤ 0 H 0 : μ d ≤ 0 H A : μ d > 0 H A : μ d > 0 (claim) H 0 : μ d = 0 H 0 : μ d = 0 H A : μ d ≠ 0 H A : μ d ≠ 0 (claim) Correct

Given that α α is 0.10 the critical value is 1.363

The test statistic is: Incorrect(round to 3 places)

The p-value is: Incorrect(round to 3 places)

In an effort to improve the mathematical skills of 18 students, a teacher provides a weekly 1-hour tutoring session. A pre-test is given before the sessions and a post-test is given after. The results are shown here. Test the claim that there was an increase in the scores. at αα=0.01. You believe that the population is normally distributed, but you do not know the standard deviation. When calculating difference use Post-test minus Pre-test.

pre-test post-test
82 80
91 90
60 58
55 51
76 74
83 79
68 66
86 84
85 81
79 83
100 91
59 61
40 47
43 49
62 61
46 45
44 36
74 82

Which of the following are the correct hypotheses?

  • H0:μd≥0H0:μd≥0
    HA:μd<0HA:μd<0(claim)
  • H0:μd≤0H0:μd≤0
    HA:μd>0HA:μd>0(claim)
  • H0:μd=0H0:μd=0
    HA:μd≠0HA:μd≠0(claim)

Given that αα is 0.01 the critical value is 2.567
The test statistic is: (round to 3 places)
The p-value is: (round to 3 places)

Solutions

Expert Solution

In an effort to improve the mathematical skills of 18 students, a teacher provides a weekly 1-hour tutoring session. A pre-test is given before the sessions and a post-test is given after. The results are shown here. Test the claim that there was an increase in the scores. at αα=0.01. You believe that the population is normally distributed, but you do not know the standard deviation. When calculating difference use Post-test minus Pre-test.

SOLUTION: H0:μd≤0
HA:μd>0 (claim)

(2) Rejection Region

Based on the information provided, the significance level is α=0.01, and the degrees of freedom are df=17.

Hence, it is found that the critical value for this right-tailed test is tc​=2.567, for α=0.01 and df=17.

The rejection region for this right-tailed test is R=t:t>2.567.

Test Statistics

The t-statistic is computed as shown in the following formula:

Decision about the null hypothesis

Since it is observed that t=−0.755≤tc​=2.567, it is then concluded that the null hypothesis is not rejected.

Using the P-value approach: The p-value is p=0.770, and since p=0.770≥0.01, it is concluded that the null hypothesis is not rejected.

(5) Conclusion

It is concluded that the null hypothesis Ho is not rejected. Therefore, there is not enough evidence to claim that the population mean μ1(POST TEST)​ is greater than μ2(PRE TEST)​, at the 0.01 significance level.

NOTE: PLEASE RE POST above question with data in tabular form.  


Related Solutions

A researcher is investigating the effects of ambient noise on the ability of rats to learn...
A researcher is investigating the effects of ambient noise on the ability of rats to learn to navigate a maze. A total of 10 rats were tested, half were randomly assigned to a no noise condition and the other half assigned to a loud ambient noise condition. For each rat, the researcher determined how many trials it took to run the maze without any errors. The results are summarized in the chart below. Rat # No Noise: Score No Noise:...
A researcher wishes to test claim that there is no difference in the life span of...
A researcher wishes to test claim that there is no difference in the life span of two types of reptiles: the Nile crocodile and giant sea turtle. Sample data including the average lifespan of both reptiles are provided below. Test the claim using α=0.05. Nile Crocodile Giant Sea Turtle X ¯ 1 = 45 s 1 ==2.6 n 1 =12 X ¯ 2 =44 s 2 =6.5 n 2 =10 State the claim: H 0 μ 1   claim H 1 μ...
2. A researcher wishes to test the claim that there is a difference in the distribution...
2. A researcher wishes to test the claim that there is a difference in the distribution of ages of elementary school, high school, and community college teachers. Teachers are randomly selected from each group. Their ages are recorded below. Can you conclude that the distributions of teachers' ages at these different levels of education are different? Use the Kruskal-Wallis test. Use α = 0.05. Elementary 28,33,32,57,42,30 High school 41,46,43,52,47,36 Comm. College 44,50,41,66,50,40 need work shown
. A researcher wishes to see if the mean number of days that a basic, low-price,...
. A researcher wishes to see if the mean number of days that a basic, low-price, small automobile sits on a dealer’s lot is 29. A sample of 30 automobile dealers has a mean of 30.1 days for this type of automobile. At an alpha 0f 0.05, test the claim that the meantime is greater than 29 days. The standard deviation (sigma) of the population is 3.8 days. a. Support the claim b. Do not support the claim
QUESTION 3 A researcher wanted to study the effects of caffeine on ability to memorize a...
QUESTION 3 A researcher wanted to study the effects of caffeine on ability to memorize a list of 16 non-related words. Additionally, the researcher was curious if extroverts or introverts would be better on the memory task and if caffeine would affect their performance differently. Given four equal conditions with 10 people in each condition, participants were either given a cup of coffee or not (depending on their condition). All participants had a 16-word list presented five times and their...
researcher wishes to investigate the effects of nitrogen fertilizer on the growth of hot pepper. The...
researcher wishes to investigate the effects of nitrogen fertilizer on the growth of hot pepper. The land available for the study is sloping in a north-south direction and appears to have a fertility gradient in an east-west direction. (a) Choose an appropriate experimental design and give reasons for your choice. (b) Write an appropriate null hypothesis. (c) Identify the target population in this study. (d) State the possible sources of variation in the experiment. (e) Provide a diagrammatic representation of...
A researcher wishes to study whether classical music has any affect on the ability to memorize...
A researcher wishes to study whether classical music has any affect on the ability to memorize information. A random sample of 51 adults were given a memory test in a quiet room. Then they were given a second memory test while listening to classical music. On the second test, 26 people received a higher score, 23 received a lower score, and 2 received the same score. A sign test at the 0.01 significance level will be used to test the...
A researcher wishes to test claim that that the average cost of a coke in Mexico...
A researcher wishes to test claim that that the average cost of a coke in Mexico is different than the average cost for a coke in Russia. The cost is measured in US Dollars. Sample data are provided below. Test the claim using α=0.10. Mexico Russia X ¯ 1 =1.26 s 1 =0.11 n 1 =14 X ¯ 2 =1.52 s 2 =0.09 n 2 =14 State the claim: H 0 μ 1     H 1 μ 1≠ μ 2 claim...
(a) A researcher wishes to test the performance of two paper shredders, the Stanley and the...
(a) A researcher wishes to test the performance of two paper shredders, the Stanley and the Bosch, designed for professional use. Each of 10 randomly selected volunteers shredded 100 sheets of paper with the Stanley, and then another sample of 10 randomly selected volunteers each shredded 100 sheets with the Bosch. The Stanley took an average of 203 seconds to shred 100 sheets with a standard deviation of 6 seconds. The Bosch took an average of 187 seconds to shred...
A tree researcher wishes to test the claim made by a colleague that trees of a...
A tree researcher wishes to test the claim made by a colleague that trees of a certain species in a forest to the north are the same height as the same species in a forest to the south. The researcher collected samples from both forests. In the northern forest, the sample size was 9 trees, the sample average was 32.7 ft, and the sample standard deviation was 6.9 ft. In the southern forest, the sample size was 12 trees, the...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT