Question

Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory. To...

Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory. To test this claim, a researcher selects a sample of n = 28 college students. Each student is given a ginkgo biloba supplement daily for 6 weeks and then all of the participants are given a standardized memory test. Scores on the standardized test are μ = 80 and standard deviation of 15. The sample of 28 students had a mean score of M = 85. (8 points) Do the data indicate a significant effect of the herb on memory? Use a two-tailed test with α = 0.05. (Show all steps.) Compute Cohen's d to measure the size of the effect IF it exists. Write a sentence describing the outcome of the hypothesis test as it would appear in a research report.

Homework Answers

Answer #1

H0: = 80

H1: 80

The test statistic z = (M - )/()  

= (85 - 80)/(15/)

= 1.76

P-value = 2 * P(Z > 1.76)

= 2 * (1 - P(Z < 1.76))

= 2 * (1 - 0.9608)

= 2 * 0.0392 = 0.0784

Since the p-value is greater than the significance level (0.0784 > 0.05), so we should not reject the null hypothesis.

There is not sufficient evidence to conclude that there is significant effect of the herb on memory.

Cohen's d = (M - )/

= (85 - 80)/15 = 0.33

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory. To...
Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory. To test this claim, a researcher selects a sample of n = 28 college students. Each student is given a ginkgo biloba supplement daily for 6 weeks and then all of the participants are given a standardized memory test. Scores on the standardized test are μ = 80 and standard deviation of 15. The sample of 28 students had a mean score of M =...
Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory. To...
Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory. To test this claim, a researcher selects a sample of n = 25 college students. Each student is given a ginkgo biloba supplement daily for six weeks and then all the participants are given a standardized memory test. For the population, scores on the test are normally distributed with m = 70 and s = 15. The sample of n = 25 students had a...
Some researchers claim that herbal supplements like ginseng enhance human memory. To test this claim, a...
Some researchers claim that herbal supplements like ginseng enhance human memory. To test this claim, a researcher selects a sample of n=30 college students. Each student is given a ginseng supplement daily for six weeks and then all of the participants are given a standard memory test. For the population, scores on the test are normally distributed with μ=80 and σ=20. The sample of n=30 students had a mean memory score of M=85. a) Are these data sufficient to show...
Some researchers claim that herbal supplements improve human memory. To test this claim, a researcher selects...
Some researchers claim that herbal supplements improve human memory. To test this claim, a researcher selects a sample of n = 25 college students. Each student is given herbal supplements daily for 6 weeks and then all the participants are given a standardized memory test. For the population, scores on the tests are normally distributed with µ = 70 and σ= 20. The sample of n = 25 students had a mean score of M = 80. Can we conclude...
Some researchers claim that herbal supplements improve human memory. To test this claim, a researcher selects...
Some researchers claim that herbal supplements improve human memory. To test this claim, a researcher selects a sample of n = 25 college students. Each student is given herbal supplements daily for 6 weeks and then all the participants are given a standardized memory test. For the population, scores on the tests are normally distributed with µ = 70 and σ= 15. The sample of n = 25 students had a mean score of M = 75. Can we conclude...
Research has claimed that sleeping 10 hours a night will enhance human memory. To test this...
Research has claimed that sleeping 10 hours a night will enhance human memory. To test this claim, a researcher selects a sample of n=25 college students. Each of the 25 students is allowed to sleep 10 hours every night in a sleep lab for 4 weeks. All of the participants are given a standardized memory test after the 4 week period. For the population, scores on the standardized memory test are normally distributed with a μ = 70 and σ...
A researcher is testing the effectiveness of a new herbal supplement that claims to improve memory...
A researcher is testing the effectiveness of a new herbal supplement that claims to improve memory performance.  A sample of n = 25 college students is obtained and each student takes the supplement daily for six week.  At the end of the 6-week period, each student is given a standardized memory test and the average score for the sample is M = 39.  For the general population of college students, the distribution of test scores is normal with a mean of µ =...
Researchers wants to know if taking the herbal supplement St. John's Wort will affect depression. First,...
Researchers wants to know if taking the herbal supplement St. John's Wort will affect depression. First, they measure the depression level of a sample of n = 4 depressed people (Pre-Test Scores). Then after a week of taking St. John's Wort, they again measure the sample's depression levels (Post-Test Scores). Note that high scores on the depression measure indicate more depression, whereas low scores indicate less depression. Participant Pre-Test Scores Post-Test Scores A 9 6 B 12 5 C 13...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT