Number of results: 18
recent suggestion is 60 min of exercise per day. A sample of 50 adults in a study of risk factor report exercising a mean of 38 min per day with a standerd deviation of 19 min .based on sampal data, is physical activity significantly less than recommended? Run the appropriate ...
Tuesday, November 20, 2012 at 1:37pm by nono
Use a one-sample z-test. z = (sample mean - population mean)/(standard deviation divided by the square root of the sample size) With your data: z = (38 - 60)/(19/√50) = ? Finish the calculation. Check a z-table at .05 level of significance for a one-tailed test. If the z...
Tuesday, November 20, 2012 at 1:37pm by MathGuru
Thanks for your help.
Wednesday, November 21, 2012 at 11:53am by nono
there are 200 subjects enrolled to receive either experimental medications or placebo. At the end of study following data is collected after 6 week. (sd)= standard deviation. BP= blood pressure. experimental meds placebo (n=100) (n=100) Mean BP 120.2(sd 15.4) 131.4(sd18.9) ...
Saturday, November 24, 2012 at 11:41pm by nono
can we use t-test for two independent sample and dichotomus study with less than five success or failures?
Wednesday, November 28, 2012 at 1:01pm by nono
I think you're asking whether a t-test is appropriate when your data consists of a binary response, i.e. a Success or a Failure, and you've got a very small number of responses. If so, the answer is no it isn't: it seems to me you ought to be looking at some sort of ...
Wednesday, November 28, 2012 at 1:01pm by David Q/R
is it true that sample size required to detect an effect size of 0.25 is larger than the sample size required to detect an effect size of 0.05 with 80% power ansd a 5% level of signisicance?
Tuesday, December 11, 2012 at 1:06pm by nono
is it true that it is more difficult to reject a null hyputhesis if we use a 10 %level of significance compared with a 5% level of significance?
Tuesday, December 11, 2012 at 5:19pm by nono
I am sorry, I do not know how one question is printed so many times. There was some problem in submission of question and when it is submitted, it is printed so many times.
Tuesday, December 11, 2012 at 5:27pm by nono
Is this statement true or false: when calculating correlation coefficient between two continous variables, the scale on which the variables are measured affect the value of the correlation coefficient.
Tuesday, December 11, 2012 at 5:31pm by nono
False. For smaller effect sizes a larger sample size would be required.
Tuesday, December 11, 2012 at 1:06pm by MathGuru
A study is conducted in patient with HIV. Lower CD4 count is associated with advance disease. The researcher is interested in finding out the relation between supplement vitamins and CD4 count. A multiple regression analysis is performed relating CD4 count to the use of ...
Tuesday, December 11, 2012 at 11:27pm by nono
A study is conducted in a patient with HIV.Lower CD4 count is associated with advance disease. A researcher is interested in the association between vitamin supplement and CD4 count.A MULTIPLE REGRESSION ANALYSIS is performed relating CD4count to the use of supplements(coaded ...
Tuesday, December 11, 2012 at 11:43pm by nono
I would say no.
Tuesday, December 11, 2012 at 5:31pm by PsyDAG
No, it is more likely to reject with 10%.
Tuesday, December 11, 2012 at 5:19pm by PsyDAG
An enzymatic method for determining alcohol in wine is evaluated by comparison with a gas-chromatography (GC) method. the same sample is analyzed several times by both methods with the following results (% ethanol). Enzymatic method: 13.1, 12.7, 12.6, 13.3, 13.3. GC method: 13...
Thursday, December 20, 2012 at 7:57pm by Jam
The following replicate calcium determinations on a blood sample using atomic absorption spectrophotometry (AAS) and a new colorimetric method were reported. Is there a significant difference in the precision of the two methods?
Thursday, December 20, 2012 at 8:00pm by Jam
Thursday, December 20, 2012 at 8:00pm by Aliza