In: Statistics and Probability
ssume that
32.632.6%
of people have sleepwalked. Assume that in a random sample of
15011501
adults,
532532
have sleepwalked.a. Assuming that the rate of
32.632.6%
is correct, find the probability that
532532
or more of the
15011501
adults have sleepwalked.b. Is that result of
532532
or more significantly high?c. What does the result suggest about the rate of
32.632.6%?
a. Assuming that the rate of
32.632.6%
is correct, the probability that
532532
or more of the
15011501
adults have sleepwalked is
nothing .
Assume that 32.6% of people have sleepwalked. Assume that in a random sample of 1501 adults,532 have sleepwalked.
a. Assuming that the rate of 32.6% is correct, find the probability that 532 or more of the 1501 adults have sleepwalked.
b. Is that result of 532 or more significantly high?
c. What does the result suggest about the rate of 32.6%?
μ = np = 1501*0.326 = 489.326
σ= √(npq) = √(1501*0.326*0.674)
=18.16055
a)
P(x>= 532) = 1- P(x<532)
=1-P(x<532-0.5) .....(using continuity correction)
=1-P(x<531.5)
For x=531.5
z=(531.5-489.326)/18.16055
=2.32
P(x<531.5) =P(z<2.32)
=0.9898
P(x>= 532) =1-P(x<531.5)
= 1-0.9898
=0.0102
b)
Since we got probability in part(a) as 0.0102 which is less than 0.05
So ,it is unusual event
Hence, Yes ,the result of 532 or more significantly high
c)
As we see that the probability result is significantly high,so rate of 32.6% is not valid
Thus,there is sufficient evidence to reject that claim that the rate is 32.6%