# statistics

For normal population mean 60, standard deviation 15, after treatment is given to the member of sample , the sample mean is 65, and sample size is 25.
is the sample mean sufficient to conclude that the treatment has significant effect? Give reason for decision?

1. 👍 0
2. 👎 0
3. 👁 172
1. Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√n

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score. Is that less than the level of significance you are using?

1. 👍 0
2. 👎 0

## Similar Questions

1. ### statistics

In a study designed to test the effectiveness of magnets for treating back pain, 40 patients were given a treatment with magnets and also a sham treatment without magnets. Pain was measured using a scale from 0 to 100. After given

asked by Sharie on November 19, 2013

A group of 894 women aged 70-79 had their height and weight measured. The mean height was 159 cm with a standard deviation of 5 cm and the mean weight was 65.9kg with a standard deviation of 12.7kg. Both sets of data are fairly

asked by Candice on June 21, 2016
3. ### Statistics

A population has a mean of   30 and a standard deviation of   5. a. If 5 points were added to every score in the population, what would be the new values for the mean and standard deviation? b. If every score in the population

asked by Nickie on January 26, 2013
4. ### statistics

Ina study designed to test the effectiveness magnets for treating back pain, 35 patients were given a treatment with magnets and also a sham treatment without magnets. Pain was measured using a scale from 0(no pain) to 100(extreme

asked by anonymous on November 18, 2013
5. ### statistics

A consumer group wants to know if an automobile insurance company with thousands of customers has an average insurance payout for all their customers that is greater than \$500 per insurance claim. They know that most customers

asked by Anonymous on April 6, 2020
1. ### Statistics

1) A sample of 49 observations is taken from a normal population. The sample mean is 55 and the sample standard deviation is 10. Determine the 99% confidence interval for the population mean. 2) The Fox TV network is considering

asked by McKenzie on July 11, 2012
2. ### statistics

what are the mean and standard deviation of a sampling distribution consisting of samples of size 16? these sameples were drawn from a population whose mean is 25 and who standard deviation is 5. a. 25 and 1.25 b. 5 and 5 c. 25

asked by helga on February 1, 2009
3. ### statistics

A normal population has a mean of 21 and a standard deviation of 5. Compute the z value associated with 24 What proportion of the population is between 21 and 24? What proportion of the population is less than 18?

asked by Barbara on November 21, 2010
4. ### AP

The composite scores of students on the ACT college entrance examination in a recent year had a Normal distribution with mean µ = 20.4 and standard deviation = 5.8. 1) What is the probability that a randomly chosen student scored

asked by Erica L on February 2, 2011
5. ### Statistics

The t distribution should be used when ___. the sampling population is not normal the sampling population is unimodal The sampling distribution is normal and the population standard deviation is unknown the population standard

asked by John on June 22, 2010
6. ### statistics

An SRS of size n is taken from a large population whose distribution of income is extremely right-skewed and the mean income is calculated. Which of the following statements is false? a) When n > 30, the sampling distribution of

asked by Anna on April 17, 2012