t-test
two-means
Example
A study was done to see if there is a difference between the number of sick days people without children take and the number of sick days people with children take. A random sample of 9 childless people found that the mean of the number of sick days taken was 5.5. The standard deviation of the sample was 1.23. A random sample of 7 people with at least one child found that the mean was 4.3 days and a standard deviation of 1.19 days. At \(\alpha=0.05\), can it be concluded that there is a difference in the means?
Step 1:
Identify the hypothesis and claim
\[H_0:\mu_1-\mu_2=0\;\;\;\;\;\;\; H_1:\mu_1- \mu_2\neq0\text{ (Claim)}\]
Step 2:
Collect the data
\[n_1=9\]
\[n_2=7\]
\[\overline{x}_1=5.5\]
\[\overline{x}_2=4.3\]
\[s_1=1.23\]
\[s_2=1.19\]
\[\alpha=0.05\]
Step 3:
Plug into the hypothesis Calculator!
Now you can use any method and you have all of the needed data. Let's do my favorite P-Value
Step 4:
Analysis and conclusion.
Note that \(p>1-\frac{\alpha}{2}\) i.e.
\[0.975679>0.975\]
hence we reject \(H_0\) and there is enough evidence to support the claim.