Homework SourseDo males and females consume different amounts of sweetened
Do males and females consume different amounts of sweetened soft drinks? A study compared male and female students in the 4th grade. The study recorded the daily intake (in fluid ounces) of sodas, fruit drinks and other sweetened drinks of 20 males and 20 females. The resulting summary statistics are given below.
We would like to perform a test of hypothesis based on the pooled variance. Calculate the pooled VARIANCE in this situation. (give your answer to 2 decimal places)
| Gender | n | mean | St. dev |
| male | 20 | 18.3 | 12.6 |
| female | 20 | 15.4 | 10.2 |
Solution
X (Mean)=18.3; Standard Deviation (s.d1)=12.6
Number(n1)=20
Y(Mean)=15.4; Standard Deviation(s.d2)=10.2
Number(n2)=20
Value Pooled variance S^2= (n1-1*s1^2 + n2-1*s2^2 )/(n1+n2-2)
S^2 = (19*158.76 + 19*104.04) / (40- 2 )
S^2 = 131.4
