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9.3.5-T A study was done using a treatment group and a placebo group. The result

ID: 3310564 • Letter: 9

Question

9.3.5-T

A study was done using a treatment group and a placebo group. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a

0.01

significance level for both parts.

Treatment      Placebo

            1              2

n            25               38

x             2.31           2.62

s             0.98           0.67

What are the null and alternative hypotheses?

The test statistic, t, is----. (Round to two decimal places as needed.

The P-value is ---. (Round to three decimal places as needed,

State the conclusion for the test.b.

Construct a confidence interval suitable for testing the claim that the two samples are from populations with the same mean.. nothingless than<mu 1 minus mu 212less than<nothing (Round to three decimal places as needed.)

Explanation / Answer

H0 : 1 = 2 Ha : 1 2

Here population standard deviation are not equal that means degree of freedom = [st2 /nt + sp2 /np] 2 / [(1/nt -1) (st2 /nt)2 + (1/np -1) (sp2 /np)2 ]

t statistic = -1.12

p value = 0.267

Conclusion: fail to rehject the null hypothesis

Confidence interval:
-0.574<u1-u2<0.114