Find the standardized test statistic to test the claim that μ1=μ2. Two samples are randomly selected from each population. The sample statistics are given below.
n1=​40, n2=​35, x1=19​, x2=20 ,σ1=​2.5, σ2=2.8
A.
2.6
B.
−1.0
C.
−0.8
D.
−1.6