In: Statistics and Probability
You wish to test the following claim (HaHa) at a significance
level of α=0.10.
Ho:μ1=μ2
Ha:μ1≠μ2
You obtain the following two samples of data.
Sample #1 | Sample #2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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What is the test statistic for this sample? (Report answer accurate
to three decimal places.)
test statistic =
What is the p-value for this sample? For this calculation, use the
degrees of freedom reported from the technology you are using.
(Report answer accurate to four decimal places.)
p-value =
Solution:-
State the hypotheses. The first step is to state the null hypothesis and an alternative hypothesis.
Null hypothesis: u1 = u 2
Alternative hypothesis: u1
u 2
Note that these hypotheses constitute a two-tailed test.
Formulate an analysis plan. For this analysis, the significance level is 0.10. Using sample data, we will conduct a two-sample t-test of the null hypothesis.
Analyze sample data. Using sample data, we compute the standard error (SE), degrees of freedom (DF), and the t statistic test statistic (t).
SE = sqrt[(s12/n1) +
(s22/n2)]
SE = 2.77614
DF = 93
t = [ (x1 - x2) - d ] / SE
t = 1.19
where s1 is the standard deviation of sample 1, s2 is the standard deviation of sample 2, n1 is the size of sample 1, n2 is the size of sample 2, x1 is the mean of sample 1, x2 is the mean of sample 2, d is the hypothesized difference between the population means, and SE is the standard error.
Since we have a two-tailed test, the P-value is the probability that a t statistic having 93 degrees of freedom is more extreme than -1.19; that is, less than -1.19 or greater than 1.19.
Thus, the P-value = 0.237.
Interpret results. Since the P-value (0.237) is greater than the significance level (0.10), we have to accept the null hypothesis.