Recent Homework Questions About Statistics
A group of 49 randomly selected construction workers has a mean age of 22.4 years with a standard deviation of 3.8. According to a recent survey, the mean age should be mu=21.9. Test this hypothesis by constructing a 98% confidence interval for the population mean.
Tuesday, November 19, 2013 at 6:31pm
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 the magnet treatments, the 40 patients had ...
Tuesday, November 19, 2013 at 6:20pm
The best point estimate is 98.2.
Tuesday, November 19, 2013 at 5:57pm
A study of the time spent shopping in a supermarket for a market basket of 20 specific items showed an approximately uniform distribution between 20 minutes and 40 minutes. What is the probability that the shopping rime will be a. Between 25 and 30 minutes? b. less than 35 ...
Tuesday, November 19, 2013 at 10:54am
given the following p values which would be considered more significant? a) p ≤ 0.3 b) p ≤ 0.02 c) p ≤ 0.25
Tuesday, November 19, 2013 at 10:44am
How could you reword these research hypotheses to null hypotheses? a. Smoking during pregnancy increase the risk of a child being born prematurely. b. Regular exercises in older adults decreases blood pressure levels.
Tuesday, November 19, 2013 at 10:37am
Create a null hypothesis for the following research questions: a. What are the differences between emergency room shifts on medication errors? b. On a clinical trial of a new drug, what will be the effects over a currently used drug?
Tuesday, November 19, 2013 at 10:34am
a. The best point estimate is 98.2 b. 98.2 - 2.575 * 0.64/sqrt(n) < u< 98.2 + 2.575 * 0.64/sqrt(n) This suggests that the mean body temperature could be lower than 98.6 ̊F.
Tuesday, November 19, 2013 at 5:34am
Im a medical student and i need to evaluate the Association between depression to cardiovascular disease. 1. what Type of Research Studies makes sense to do? 2.Design (Study period, epidemiological approach...) 2. Who are the participants in study and how will be selected? (...
Tuesday, November 19, 2013 at 5:16am
2. Betty, an employee of Shining Sun Daycare Center, read an article in Healthy Child Magazine saying that the average 3-year-old child is 37 in. tall. Betty works with 3-year-olds at Shining Sun, so later that week, she measured the height of each child who had just turned or...
Monday, November 18, 2013 at 11:25pm
The larger the sample size, the more you can safely approximate the normal distribution.
Monday, November 18, 2013 at 11:00pm
Assume that a test is given to a large number of people but we do not yet know their scores or the shape of the score distribution. Can we be sure that the sampling distribution of the mean for this test will be normally distributed? Why or why not? Answer this Questi
Monday, November 18, 2013 at 9:48pm
mean = 1008/15 = 67.2 sd =sqrt(140.4/14) = 3.167 z = (x1 - 67.2)/3.167 x1 = 1*3.167 + 67.2 = 70.37 z = (x2 - 67.2)/3.167 -1 = (x2 - 67.2)/3.167 x2 = -1*3.167 + 67.2 = 64.033 The ages are 60 and 70 respectively.
Monday, November 18, 2013 at 9:18pm
Answered in a later post.
Monday, November 18, 2013 at 8:49pm