Asked Nov 8, 2019

.    A medical researcher wishes to see whether the pulse rate of smokers are higher than the pulse rates of non-smokers.  Samples of 100 smokers and 100 nonsmokers are selected. The results are shown below.  Can the researcher conclude at an alpha = 0.05, that smokers have higher pulse rates than nonsmokers?





Mean = 90

Mean = 88

Standard Deviation = 5

Standard Deviation = 6


Expert Answer

Step 1

Hypotheses for the test is given below:

Let µ1 is the mean pulse rate for smokers and µ2 is the mean pulse rate for nonsmokers.


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Ho 4

Step 2

Test statistic for t-test:

Since population standard deviations are unknown, the appropriate test is two sample t-test.

Here, the sample means for smokers and nonsmokers are 90 and 88 respectively.

Sample standard deviations of smokers and nonsmokers are 5 and 6 respectively.

The sample sizes of smokers and nonsmokers are 100 and 100 respectively.

The pooled standard deviation can be calculated as follows:


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(n,-1)s+(n,-1)s п+п,—2 (100-1)25 +(100-1)36 100100-2 =5.5227

Step 3


The test statistic for t-test is c...


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| 1 1 п п, 90-88 1 5.5227 100 100 -2.5607 2.561


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