A researcher records the following response times to a visual stimulus: 23 ± 3.1 (M ± SD) s. Assuming these data are normally distributed, what is the probability that participants responded in 20 s or less

0.1666

Step-by-step explanation:

A researcher records the following response times to a visual stimulus: 23 ± 3.1 (M ± SD) s. Assuming these data are normally distributed, what is the probability that participants responded in 20 s or less

z=X-U/SD

z = (20-23) / 3.1

z=-0.9677

checking the negative part of the z score table. we go to

-0.97

that is - 0.9 under 0.07

the value we get is 0.1666

P (x<20) means that P (z<-0.97)

0.1666