Reaction time studies are studies in which participants receive a stimulus and t

Question

Reaction time studies are studies in which participants receive a stimulus and the amount of time it takes for them to react is measured. In one simple type of reaction time study, each participant holds a clicker button and stares at a screen. When the participant sees a part of the screen light up, he or she clicks the button as quickly as possible. The researcher then records how much time elapsed between when the screen lit up and when the participant clicked the button. Suppose that, in these tests, the distribution of reaction times is skewed slightly to the right. Suppose also that mean reaction time is 190 milliseconds, and the standard deviation for reaction times is 20 milliseconds (for the purposes of this problem, you can treat the mean and standard deviation as population parameters). Use this information to answer the following questions, and round your answers to four decimal places. a. Suppose we have 11 different people take this reaction time test. What is the probability that the average of these 11 reaction times will be greater than 186 milliseconds? Incorrect: Your answer is incorrect. b. Suppose we have 13 different people take this reaction time test. What is the probability that the average of these 13 reaction times will be less than 192 milliseconds? c. Suppose we have 27 different people take this reaction time test. What is the probability that the average of these 27 reaction times will be less than 184 milliseconds? d. Would it be appropriate to use the normal probability app to compute the probability that a single reaction time is less than 184 milliseconds?

Explanation / Answer

mean = 190 , s = 20

a)
n = 11
P(x >186)

= (186 - 190)/(20/sqrt(11))
= -0.6633

P(x >186) = P(z > -0.6633) = 0.7464

b)
n = 13

P(x < 192)

= (192 - 190)/(20/sqrt(13))
=0.3606

P(x < 192) = P(z < 0.3606) = 0.6408

c)
n = 27

P(x < 184)

= (184 - 190)/(20/sqrt(27))
= -1.5588

P(x < 184) = P(z < -1.5588) = 0.0595

d)
yes

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.