Question

One of the assumptions for ANOVA, the variances of the populations:

Select one:

A. must be greater than F critical value

B. must be less than F critical value

C. must be different  

D. must be equal.

A cell phone company found that 75% of all customers want text messaging on their phones, 80% want photo capability, and 65% want both. What is the probability that a customer who wants text messaging also wants photo capability?

Select one:

A. 0.60

B. 0.87

C. 0.81

D. 0.90

Answer 1

a)

Assumptions for ANOVA :

In general there are three assumptions of one way ANOVA.

• The populations from which the samples were obtained must be normally or approximately normally distributed.
• The samples must be independent.
• The variances of the populations must be equal.

So the correct option is D.

That is the variance of the population must be equal.

b)

Suppose,

A : customers want text messaging.

B : Customers want photo capability.

We are given

75 % customer want text messaging.

80% customer want photo capability.

65% customer want both.

In probability,

P ( A ) = 0.75

P ( B ) = 0.80

P ( A or B ) = 0.65

We need to find the

The probability that a chosen person wants text messaging and photo capability. That means P ( A and B ).

We can find this probability by using the addition rule for the probability.

P ( A or B ) = P ( A ) + P( B ) - P ( A and B)

By rearranging this formula.

P ( A and B ) = P ( A ) + P ( B ) - P ( A or B )

= 0.75 + 0.80 - 0.65

= 1.55 - 0.65

= 0.90

So the correct option is D.

The probability that a chosen person wants text messaging and photo capability is 0.90.