statistics
posted by sai .
You are conducting an experiment to see if a given therapy works to reduce test
anxiety in a sample of college students. A standard measure of test anxiety is known to
produce a = 19. In the sample you draw of 86 the mean is equal 17.5 with standard
deviation s = 10.
a Use an level of 0.05 to test the hypothesis that the mean is less than 19.
b Find the 95 % one sample con dence interval for the mean.

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. Remember that your hypothesis leads to a onetailed test.
95% = mean ± 1.96 SEm
Respond to this Question
Similar Questions

Statistics
The Computer Anxiety Rating Scale (CARS) measures an individual's level of computer anxiety, on a scale from 20 ( no anxiety) to 100 (highest level of anxiety). Researchers at Miami University administered CARS to 172 business students. … 
statistics
Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4 There are 200 students in a sample. How many of these students will have scores … 
Statistics
Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. There are 200 students in a sample. How many of these students will have scores … 
statistics
The Frayed Nerves Anxiety Scale (FNAS) is used to measure the anxiety level of people on a scale from 0 to 1000. Four students were randomly chosen and given the FNAS before their second exam. Their scores were 700, 653, 740, and 707. … 
Statistics
I bemieve the t test is paired , want to make usre beofre I run the stats. A researcher wanted to answer the following question: What is the difference in students' computer anxiety based on whether or not they own computers? 
statistics
a random sample of 80 college students was selected to participate in a experiment. the mean of the sample is 317 points, the standard deviation of 37 there are 310 students that didn't complete the experiment 1. compute the appropriate … 
stats
Which test do you use to solve this problem Onesample or independent samples ttest? 
stats
Which test do you use to solve this problem Onesample or independent samples ttest? 
psychology
in his research, Dr. Caulfiel wants compare levels of tests anxiety among high school students in grade 10 and 12. His hypothesis is that seniors will have higher levels of test anxiety than sophomores will. His theoretical definition … 
statistics
1. Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and a standard deviation of 4. Do not use the web calculator to answer the following questions. Instead, …