# Multiple choice questions in statistics

Question 1: Suppose a population is normally distributed with a mean of 200 and a standard deviation of 40. The probability that x> 190 is:

.5987

.4013

.7671

.0987

Question 2: Another name for the normal distribution is:

exponential distribution

Gaussian distribution

regular distribution

healthy distribution

Question 3: Values are uniformly distributed between 50 and 80. The height of this distribution is:

.0333

.0555

.1285

.0437

Question 4: Suppose x is normally distributed with a mean of 56. Eighty percent of the values are greater than 48. The standard deviation is approximately:

9.52

15.38

26.67

40.00

Question 5: Who of the following is not given some credit for developing or discovering the normal distribution?

Pierre-Simon de Laplace

Abraham de Moivre

Karl Gauss

Karl Pearson

Question 6: Suppose gasoline prices are uniformly distributed across the country ranging from $1.55 to $2.10. If the gasoline price at a particular location is randomly selected, the probability that the price is between $1.70 and $1.80 is:

.1818

.0182

.3333

.4072

Question 7: Suppose gasoline prices are uniformly distributed across the country ranging from $1.55 to $2.10. The mean gasoline price for this distribution is:

$1.80

$1.825

$1.85

.0182

Question 8: Suppose gasoline prices are uniformly distributed across the country ranging from $1.55 to $2.10. If the gasoline price at a particular location is randomly selected, the probability that the price is between $2.15 and $2.40 is:

.0000

.0182

.3333

.4545

Question 9: Problems from which of the following binomial distributions can be worked by the normal curve because the approximation is good enough?

n = 10, p = .50

n = 12, p = .60

n = 13, p = .70

n = 14, p = .80

Question 10: Which of the following distributions represent things that are "measured" as opposed to "counted"?

disjoint distributions

metered distributions

discrete distributions

continuous distributions

Question 11: The normal curve is sometimes referred to as the:

curve of inflection

bell-shaped curve

de Moivre's curve

unipeaked curve

Question 12: An appliance store sells washing machines and dryers among other things. The average sale on washers and dryers is $530 with a standard deviation of $100. Suppose that sales figures on washers and dryers are normally distributed. If a sale is randomly selected, the probability that it is between $650 and $700 is:

.0705

.3849

.1652

.8403

Question 13: Suppose x is normally distributed with a standard deviation of 7. Seventy-one percent of the values are less than 45. The mean is:

48.85

41.15

43.53

46.47

Question 14: In order to work a binomial distribution problem by the normal curve, what must be true?

n?p> 7

0 <=n

square root of (npq) >= 2.75

n> 5 and .4 <p< .6

n> 5 and .4 <p< .6

Question 15: Suppose a population is normally distributed with a mean of 200 and a standard deviation of 40. The probability that x< 150 is:

.1069

.2276

.1056

.3944

Question 16: A researcher is working a binomial problem using a normal curve approximation.

In the binomial problem, the researcher is trying to determine the probability of 51 <x< 56. In working the problem by the normal curve, the solution will be found at:

50.5 <x< 56.5

50.5 x 56.5

51.5 <x< 55.5

50.5 <x< 55.5

Question 17: Suppose 41% of all workers in the telecommunications industry are satisfied with their work. If 63 telecommunications workers are randomly selected what is the probability that fewer than 23 are satisfied with their work?

.1977

.2743

.2358

.3023

Question 18: A z score is:

the distance a value is from the mean

the number of standard deviations a value is above or below the mean

the probability that a value has in a normal distribution

the peakedness of the curve

Question 19: An appliance store sells washing machines and dryers among other things. The average sale on washers and dryers is $530 with a standard deviation of $100. Suppose that sales figures on washers and dryers are normally distributed. If a sale is randomly selected, the probability that it is greater than $600 is:

.7580

.2943

.2580

.2420

Question 20: Suppose 29% of all commuter cars leaving downtown at 5 P.M. are going somewhere other than home. If 45 commuter cars leaving downtown at 5 P.M. are tracked, what is the probability that more than 11 are going somewhere other than home?

.1950

.2486

.6950

.7486

Question 21: Values are uniformly distributed between 50 and 80. The probability of x> 75 is:

.0333

.3333

.1667

.0000

Question 22: Suppose the average hourly wage of a production line worker in a particular industry is normally distributed with a mean of $9.40. Sixty percent of the workers earn less than $10.25. The standard deviation is:

$1.42

$3.40

$8.50

$2.13

Question 23: A researcher is working a binomial problem using a normal curve approximation.

In the binomial problem, the researcher is trying to determine the probability of x >=13. In working the problem by the normal curve, the solution will be found at:

X >= 12.5

X >= 13.5

12.5 <=x <= 13.5

x> 13

Question 24: Values are uniformly distributed between 50 and 80. The mean of this distribution is:

.5000

65

70

.0333

Question 25: Suppose 57% of all shoppers use credit cards for their purchase in department stores. If 80 such shoppers are randomly selected, what is the probability that more than 49 use a credit card?

.3106

.1894

.2578

.2946

#### Solution Preview

Question 1

Suppose a population is normally distributed with a mean of 200 and a standard deviation of 40. The probability that x> 190 is:

0.5987

0.4013

0.7671

0.0987

Answer: 0.5987

Mean=M = 200

Standard deviation =s= 40

x= 190

z=(x-M )/s= -0.25 =(190-200)/40

Cumulative Probability corresponding to z= -0.25 is= 0.4013

Or Probability corresponding to x< 190 is Prob(Z)= 0.4013

Therefore probability corresponding to x> 190 is 1-Prob(Z)= 0.5987 =1-0.4013

0r= 59.87%

Question 2

Another name for the normal distribution is:

exponential distribution

Gaussian distribution

regular distribution

healthy distribution

Answer: Gaussian distribution

Question 3

Values are uniformly distributed between 50 and 80. The height of this distribution is:

0.0333

0.0555

0.1285

0.0437

Answer: 0.0333

0.033333333 =1/(80-50)

Question 4

Suppose x is normally distributed with a mean of 56. Eighty percent of the values are greater than 48. The standard deviation is approximately:

9.52

15.38

26.67

40

Answer: 9.52

Mean=M = 56.00

s=standard deviation= ? (to be determined)

80% of the values are greater than x= 48

Z corresponding to 20% (= 100%- 80.%) is -0.8416

z=(x-M )/s or s=(x-M ) /z*s

or s=(48-56)/-0.8416= 9.51

Question 5

Who of the following is not given some credit for developing or discovering the normal distribution?

Pierre-Simon de Laplace

Abraham de Moivre

Karl Gauss

Karl Pearson

Answer: Karl Pearson

Question 6

Suppose gasoline prices are uniformly distributed across the country ranging from $1.55 to $2.10. If the gasoline price at a particular location is randomly selected, the probability that the price is between $1.70 and $1.80 is:

0.1818

0.0182

0.3333

0.4072

Answer: 0.1818

probability= 0.1818 =(1.8-1.7)/(2.1-1.55)

Question 7

Suppose gasoline prices are uniformly distributed across the country ranging from $1.55 to $2.10. The mean gasoline price for this distribution is:

$1.80

$1.83

$1.85

0.0182

Answer: $1.83

Mean = 1.83 =(1.55+2.1)/2

Question 8

Suppose gasoline prices are uniformly distributed across the country ranging from $1.55 to $2.10. If the gasoline price at a particular location is randomly selected, the probability that the price is between $2.15 and $2.40 is:

0

0.0182

0.3333

0.4545

Answer: 0

Since the range is beyond the distribution

...

#### Solution Summary

Answers multiple choice questions in statistics on the topics of normal distribution, binomial distribution, uniform distribution, z score etc.