if there are 2 rows then each row will have 78 members
Step-by-step explanation:
4x-9=15
Solutuon
4x-9=15
4x=15-9
4x=6
x=6:4
x=1,5
X=2 and you go up on the y-intercept 2 times and move 1 right.
The answer is 5.5
The standard deviation (sd or σ) of the sample mean difference is:
sd = √(sd₁²/n₁ + sd₂²/n₂)
For the population A:
sd₁ = 17.6
n₁ = 25
For the population B:
sd₂ = 21.2
n₂ = 30
Hence:
sd = √(sd₁²/n₁ + sd₂²/n₂)
= √(17.6²/20 + 21.2²/30)
= √(309.76/20 + 449.44/30)
= √(15.49 + 14.98)
= √(30.47)
= 5.5
