Business Analytics EXAM 2 Gupta

(Chapter 4) A ____________ measure of the chance that an uncertain event will occur.

Probability

(Chapter 4) What is the value of 0?

1

(Chapter 4) Which of the following is NOT an assigning probability to sample space outcomes?

A) Classical Method

B) Wisdom Method

C) Relative Frequency Method

D) Subjective Method

Wisdom Method

(Chapter 4) When you toss a die, what is the probability that you will get a 7 on the upward face of the die?

A) 2/6

B) 3/6

C) 0/6

D) 1/6

0/6

(Chapter 4) A, B, C, D, and E are sample space outcomes forming a sample space. Suppose that:

P(A)= 0.3

P(B)= 0.1

P(C)= 0.4

P(E)= 0.1

What is P(D)=

0.1

(Chapter 4) What is the probability that the couple will have at least 1 girl?

7/8

(Chapter 4) Let A, B, and C be events and assume the following probabilities.

P(A)= 0.2

P(B)= 0.3

P(C)= 0.5

P(A∩B)= 0.06

P(A∩C)= 0

P(B∩C)= 0.5

What two events are mutually exclusive?

A and C

(Chapter 4) Consider randomly selecting a card from a standard deck of 52 playing cards. What is the probability that the randomly selected card is an ace or a king?

4 Kings

4 Aces

8/52

(Chapter 4) If A and B are independent events, P(A)= 0.2 and P(B)= 0.7 determine (A∩B).

P(A∩B)=P(A)×P(B)

0.14

(Chapter 4) What is the probability that customers have television service A?

(12.4/27.4)=

0.45

(Chapter 4) How many combinations of 3 high-risk stocks could you randomly select from 7 high-risk stocks?

N=7

n=3

35

(Chapter 6) Shoe size is an example of a

discrete variable

(Chapter 6) Which of the following is not a continuous random variable?

(The "number of" means DISCRETE)

the number of apples needed for making apple jelly

(Chapter 6) Which of the following is NOT a property of discrete probabilities?

(Must be positive and a whole number).

Depending on the risky situation, probabilities can have negative values and better estimates.

(Chapter 6) An insurance policy sells a $25,000 whole life insurance policy for an annual premium of $400. Actuaries' tables show that a person who would be sold such a policy with a premium has 0.002 probability of death during a year. Let x be the random variable representing the company's profit made on one of their policies during a year. The probability of distribution is

$400(0.998)+(-24,600)(0.002)

$351.20 "?" "350"

Suppose that historical records indicate that 30% of all customers who enter a discount department store make a purchase. What is the probability that four of the next five will make a purchase?

5 * (0.3)^4 * (0.7)

0.02835

Suppose that x is a binomial random variable with n=5, p=0.3, and q=0.7. Calculate the mean.

Mean=n*p

1.5

Suppose that x is a binomial random variable with n=5, p=0.3, and q=0.7. Calculate the variance.

1.05

Suppose that x is a binomial random variable with n=5, p=0.3, and q=0.7. Find p(x=0).

(0.7)^5

0.1681

The ________ of two events A and B is the event that consists of the sample space outcomes belonging to both A and B.

Intersection

If events A and B are mutually exclusive, calculate P(A|B)

0

An _________ is the probability that one event will occur given what we know that another event has already occurred.

Conditional Probability

Which of the following is not a characteristic of a binomial experiment?

Each characteristic is dependent on each other.

If the mean= 5.5 and variance= 9, what is the value of standard deviation?

√npq

3

Which of the following is not a type of continuous random distribution?

Binomial

Which of the following is a not a continuous graph?

Bar Graph

Which of the following are not properties of normal distribution?

The shape of any individual curve depends on median and mode.

__________ standard deviations result in normal curves that are flatter and more spread out (wider).

Large

A standard normal distribution (or curve) has

mean of 0 and standard deviation of 1

Suppose that the random variable x has a uniform distribution with c=3 and d=7. Find the mean.

5

If Mean= 2.1 and Standard Deviation= 0.9434. Find the probability that x will lie in the interval mean plus/minus 2 standard deviation.

2.1 - 2(0.9434)= 0.2132

2.1 + 2(0.94340= 3.9868

(0.2132, 3.9668)

What does this formula represent? n!/(x! (n - x)!

the number of ways to arrange a successful among n trails

Probabilities must be assigned to sample space outcomes so that the probability assigned to each sample space outcome must be between ________, inclusive.

0 and 1

Find P(Z= -3.13)

.00087

Find P(Z < -3.59)

.00017

_____________ measure the spread of normal curve.

variance and standard deviation

Let x be a normally distributed random variable having the mean = 30 and standard deviation = 5. Find the value when x = 50.

(50-30)/5

4

Consider the figure given below. Find the value h that makes the function f(x) a valid continuous probability distribution.

1/75

Suppose that the random variable x is normally distributed with mean = 900 and standard deviation = 90. Find the probability P(x > 1000) (round the z value to 2 decimals).

0.1335

X is poisson with

0.1353