In: Math
A researcher wants to study the relationship between salary and gender. She randomly selects 330 ... A researcher wants to study the relationship between salary and gender. She randomly selects 330 individuals and determines their salary and gender. Can the researcher conclude that salary and gender are dependent?
Income Male Female Total
Below $25,000 25 16 41
$25,000-$50,000 47 103 150
$50,000-$75,000 48 32 80
Above $75,000 36 23 59
Total 156 174 330
Step 1 of 8: State the null and alternative hypothesis. Step 2 of 8: Find the expected value for the number of men with an income below $25,000. Round your answer to one decimal place. Step 3 of 8: Find the expected value for the number of men with an income $50,000-$75,000. Round your answer to one decimal place. Step 4 of 8: Find the value of the test statistic. Round your answer to three decimal places. Step 5 of 8: Find the degrees of freedom associated with the test statistic for this problem. Step 6 of 8: Find the critical value of the test at the 0.01 level of significance. Round your answer to three decimal places. Step 7 of 8: Make the decision to reject or fail to reject the null hypothesis at the 0.01 level of significance. Step 8 of 8: State the conclusion of the hypothesis test at the 0.01 level of significance.
Observed | Oi | <25000 | 25000-50000 | 50000-75000 | >75000 | Total |
male | 25 | 47 | 48 | 36 | 156 | |
female | 16 | 103 | 32 | 23 | 174 | |
Total | 41 | 150 | 80 | 59 | 330 | |
Expected | Ei=Σrow*Σcolumn/Σtotal | <25000 | 25000-50000 | 50000-75000 | >75000 | Total |
male | 19.3818 | 70.9091 | 37.8182 | 27.8909 | 156 | |
female | 21.6182 | 79.0909 | 42.1818 | 31.1091 | 174 | |
Total | 41 | 150 | 80 | 59 | 330 | |
chi square χ2 | =(Oi-Ei)2/Ei | <25000 | 25000-50000 | 50000-75000 | >75000 | Total |
male | 1.6285 | 8.0617 | 2.7413 | 2.3577 | 14.789 | |
female | 1.4601 | 7.2277 | 2.4577 | 2.1138 | 13.259 | |
Total | 3.089 | 15.289 | 5.199 | 4.471 | 28.0483 |
step 1:null hypothesis:salary and gender are independent
alternate hypothesis:Ha salary and gender are not independent
Step 2 of 8: expected value for the number of men with an income below $25,000 =19.4
Step 3 :expected value for the number of men with an income $50,000-$75,000=37.8
Step 4 of 8: value of the test statistic. =28.048
Step 5 of 8:
degree of freedom(df) =(rows-1)*(columns-1)= | 3 |
Step 6 of 8:
for 3 df and 0.01 level of signifcance critical region χ2= | 11.345 |
Step 7 of 8:
reject the null hypothesis
Step 8 of 8:there is sufficient evidence........