inference for two means

Question 1

sample statistic

Answer 1

xbar1 - xbar2
difference in the two sample means

Question 2

population parameter

Answer 2

mu1 - mu2
difference in the two population means

Question 3

sampling distribution is nearly normal when..

Answer 3

independence within each sample (random samples)
independence between each sample (observations in one sample tells us nothing about the observations in the other sample)
normality

Question 4

hypothesis test

Answer 4

Ho: mu1-mu2 =0
Ha: mu1-mu2=/0, mu1-mu2>0,mu1-mu2<0

Question 5

test statistic

Answer 5

t-value
tells us the degree of difference between the two sample means from what we would expect if the null hypothesis were true and the difference between the two means was 0
ex. t= 5.6
the difference between the two sample means is 5.6 standard deviations above the expected value