Question

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 that the memory scores of the sample after the “herbal supplement” treatment are significantly greater than those of the general population(population mean before treatment)? Perform a hypothesis test using a z- score statistic. Use a one-tailed test with α = .05.

The critical z-value is

Homework Answers

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 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...
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 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 = 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 =...
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 =...
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...
Many people take ginkgo supplements advertised to improve memory. Are these over-the-counter supplements effective? In a...
Many people take ginkgo supplements advertised to improve memory. Are these over-the-counter supplements effective? In a study reported in the paper “Ginkgo for memory Enhancement” (Journal of the American Medical Association), elderly adults were assigned at random to either a treatment or a control group. The 104 participants who were assigned to the treatment group took 40 mg of ginkgo three times a day for six weeks. The 115 participants assigned to the control group took a placebo pill three...
Suppose that memory for unrelated words is distributed normally with a mean of µ = 50...
Suppose that memory for unrelated words is distributed normally with a mean of µ = 50 with a standard deviation of σ = 12. A random sample is selected from this population. After a treatment is administered to the individuals in the sample, a memory test that measures memory for unrelated words is administered, the sample mean is found to be M = 55. If the sample consists of n = 16 scores, can we conclude that the treatment has...
A researcher selects a sample of n = 100 from a normal population with µ =...
A researcher selects a sample of n = 100 from a normal population with µ = 50 and σ = 30. If the treatment is expected to decrease scores by 10 points, what is the power of a two-tailed hypothesis test using α = .05?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT