Question

Internet Access Of U.S. households, 67% have Internet access (based on data from the Census Bureau). In a random sample of 250 households, 70% are found to have Internet access. Find the probability that should be used to determine whether the 67% rate is too low.

Group of answer choices

answers

a. 0

b. 1

c. 0.1736

d. 0.8264

Answer 1

BIONOMIAL DISTRIBUTION
pmf of B.D is = f ( k ) = ( n k ) p^k * ( 1- p) ^ n-k
where   
k = number of successes in trials
n = is the number of independent trials
p = probability of success on each trial
I.
mean = np
where
n = total number of repetitions experiment is executed
p = success probability
mean = 250 * 0.7
= 175
II.
variance = npq
where
n = total number of repetitions experiment is executed
p = success probability
q = failure probability
variance = 250 * 0.7 * 0.3
= 52.5
III.
standard deviation = sqrt( variance ) = sqrt(52.5)
=7.2457
a.
probability that should be used to determine whether the 67% rate is too low
P( X = 0.67 ) = ( 250 0.67 ) * ( 0.7^0.67) * ( 1 - 0.7 )^249.33
= 0
option:a