SOLUTION: hirty percent of salespersons in ABC Ltd. are male. A random sample of 100 salespersons is selected. (a) Which distribution does this scenario fit and why? (b) Define the varia

Algebra ->  Probability-and-statistics -> SOLUTION: hirty percent of salespersons in ABC Ltd. are male. A random sample of 100 salespersons is selected. (a) Which distribution does this scenario fit and why? (b) Define the varia      Log On


   



Question 1109930: hirty percent of salespersons in ABC Ltd. are male. A random sample of 100
salespersons is selected.
(a) Which distribution does this scenario fit and why?
(b) Define the variable of interest, X.
(c) What are the possible values of X?
(d) What is the expected number of males?
(e) What is the standard deviation of the number of males?
(f) What is the probability that there are exactly 25 males in the sample?
(g) What is the probability of getting less than 36 males?

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
This is a 1 sample proportion test
x is the random variable and the proportion of those chosen who are male
possible values are [0, 100], integers only.
E(X)=np=0.3*100=30.
V(X)=np(1-p)=30*0.7=21
sd is sqrt (21) or 4.6
probability of 24 males is 100C25*0.3^25*0.7^75=0.0496
getting fewer than 36 using normal approximation at 35.5
(35.5-30)/4.6 is z
z=+1.20
probability that z < 1.20 is 0.8849.