Question

PART I

The revenue of 200 companies is plotted and found to follow a bell curve. The mean is $387.142 million with a standard deviation of $28.2876 million. Would it be unusual for a randomly selected company to have a revenue below $267.32 million?

1)	It is impossible for this value to occur with this distribution of data.

2)	The value is unusual.

3)	We do not have enough information to determine if the value is unusual.

4)	The value is not unusual.

5)	The value is borderline unusual.

PART II

Pinterest claims that 0.3154 of their app users are men. In a sample of 72 randomly chosen app users, what is the probability that no more than 28 of them will be men?

1)

0.0202

2)

0.0403

3)

0.9270

4)

0.0730

5)

0.8867

PART III

Fill in the blanks. After conducting research around the country, Ford Motor Company determined that the probability of a randomly selected Ford vehicle on the road being driven by a female is 0.69. If there are 4,823 Ford vehicles in your town, around __________ cars will be driven by females, give or take __________. Assume each car represents an independent trial.

1)	3,327.87 , 1,031.60

2)	3,327.87 , 0.69

3)	3,327.87 , 32.119

4)	4,823 , 32.119

5)	32.119 , 3,327.87

Answer 1

1)

z score for 267.32 =(X-mean)/std deviation =(267.32-387.142)/28.2876 =-4.24

since z score is less than -2

2)	The value is unusual.

part II:

here mean of distribution=μ=np=		22.71
and standard deviation σ=sqrt(np(1-p))=		3.9429
for normal distribution z score =(X-μ)/σx

probability =P(X<28.5)=(Z<(28.5-22.7088)/3.94)=P(Z<1.47)=0.9270

option 3) 0.9270 is correct

part III)

here mean of distribution=μ=np=		3327.87
and standard deviation σ=sqrt(np(1-p))=		32.1191

Correct option is : 3 3,327.87 , 32.119