T-Tests and Chi2. Does your sample data reflect the population from which it is drawn from?. Single Group Z and T-Tests.
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Does your sample data reflect the population from which it is drawn from?
For α =.05 and N=30 , t =2.045
20± 2.086 (5/19) =
H1: watching campaign commercials increases consumption of Twinkies (snackie cakes), or μ1≠ μ2
Null is μ1= μ2
After one group watches the commercials, but not the other, we measure Twinkie in-take. We find that indeed the group exposed to political commercials indeed ate more Twinkies. We thus conclude that political advertising leads to obesity.
Pooled variance of the two groups
= common standard deviation of two groups
Females: mean = 50.9, variance = 47.553, n=6
Males: mean=41.5, variance= 49.544, n=10
Also, hypothesis testing can entail a one or two-tailed test, depending on if a hypothesis is directional (increase/decrease) in nature.
Obtained Value: 2.605
Degrees of Freedom: number of cases left after subtracting 1 for each sample.
Is the null hypothesis supported?
Answer: Indeed, women have higher verbal skills and this is statistically significant. This means that the mean scores of each gender as a population are different.
n = number of paired groups
Given the sample size, how many cases could we expect in each category (n/#categories)? The obtained/critical value estimation will provide a coefficient and a Pr. that the results are random.