In: Statistics and Probability
A global research study found that the majority of today's working women would prefer a better work-life balance to an increased salary. One of the most important contributors to work-life balance identified by the survey was "flexibility," with 41% of women saying that having a flexible work schedule is either very important or extremely important to their career success. Suppose you select a sample of 100 working women. Answer parts (a) through (c).
If a sample of 400 is taken, how does this change your answers to (a) through (c)?
A) The probability that in the sample fewer than 47% say that having a flexible work schedule is either very important or extremely important to their career success is?
B) The probability that in the sample between 36% and 47% say that having a flexible work schedule is either very important or extremely important to their career success is?
C) The probability that in the sample more than 37% say that having a flexible work schedule is either very important or extremely important to their career success is?
a)
population proportion ,p= 0.41
n= 400
std error , SE = √( p(1-p)/n ) = 0.024592
sample proportion , p̂ = 0.47
Z=( p̂ - p )/SE= 2.440
P ( p̂ < 0.47 ) =P(Z<( p̂ - p )/SE)
=
=P(Z < 2.440 ) =
0.9927
The probability that in the sample fewer than 47% say that having a flexible work schedule is either very important or extremely important to their career success is 0.9927
B)
population
proportion ,p= 0.41
n= 400
std error
, SE = √( p(1-p)/n ) = 0.0246
we need to
compute probability for
0.36 < p̂ < 0.47
Z1 =( p̂1
- p )/SE= -2.033
Z2 =( p̂2
- p )/SE= 2.440
P( 0.36 < p̂ <
0.47 ) = P[( p̂1-p )/SE< Z
<(p̂2-p)/SE ] =P( -2.033
< Z < 2.440 )
= P ( Z < 2.440 ) - P (
-2.033 ) = 0.9927
- 0.021 =
0.9716
The probability that in the sample between 36% and 47% say that
having a flexible work schedule is either very important or
extremely important to their career success is = 0.9716
-------------------------
c)
population proportion ,p= 0.41
n= 400
std error , SE = √( p(1-p)/n ) = 0.025
sample proportion , p̂ = 0.37
Z=( p̂ - p )/SE= -1.627
P ( p̂ > 0.37 ) =P(Z > ( p̂ - p
)/SE) =
=P(Z > -1.627 ) =
0.9481
The probability that in the sample more than 37% say that having a flexible work schedule is either very important or extremely important to their career success is 0.9481