Atreatment is administered to a sample of n = 9 individuals selected from a population with a mean of µ = 80 and a standard deviation of σ = 12. after treatment, the effect size is measured by computing cohen’s d, and a value of d = 0.50 is obtained. based on this information, what is the mean for the treated ) m = 82(b) this cannot be answered without knowing the sample size.(c) m = 6(d) m = 86

a) M =82

Step-by-step explanation:

Let´s study this as a Normal distribution.

As we know in a normal distribution the z score is = (X-μ)/(sd/sqrt(n))

where

X = mean for the taken sample = What we want to know in this problem

μ = Total population mean =80

sd= standard deviation= 12

n = sample size=9

So in this case z=( X-80)/(12/sqr(9))= (X-80)/4

also we know that the effect size taken by the machine is 0.5, which is the same as the z-score

so...

0.5 = (X-80)/4 => 0.5*4 = X-80

2+80 = X

X = 82