Question

The frequency table represents the results of a survey comparing the average age of household members to the way that they watch non-network television.
(Image 1)


Madigan converts the frequency table to a conditional relative frequency table by row.

Television Viewing Method
(Image 2)



Which value should she use for X? Round to the nearest hundredth.

Answer 1

From the first table:

1) $n(\text{Under 40 and Internet})=54;$

2) $n(\text{Under 40 and Cable})=81;$

3) $n(\text{40 or older and Internet})=23;$

4) $n(\text{40 or older and Cable})=92.$

Then you can fill the second table:

1)

$p(\text{Under 40 and Internet})=w=\dfrac{54}{250}=0.216;$

2)

$p(\text{Under 40 and Cable})=y=\dfrac{81}{250}=0.324;$

3)

$p(\text{40 or older and Internet})=x=\dfrac{23}{250}=0.092;$

4)

$p(\text{40 or older and Cable})=z=\dfrac{92}{250}=0.368.$

Answer: she should use for $x=0.092\approx 0.09.$

Answer 2

For X they would divide the number from the first chart for average household age 40 or under, which is 23, by the total internet, which is 77.

X = 23/77 = 0.2987, which would round to 0.30