Question

the relative frequency table shows the results of a survey in which parents were asked how much time their children spend playing outside and how much time they spend using electronics.

time spent by children

	at least 1 hr/day using electronics	less than 1 hr/day using electronics	total
less than 1 hr/day outside	42	6	48
total	44	20	64

given that a child spends at least 1 hour per day outside, what is the probability, rounded to the nearest hundredth if necessary, that the child spends less than 1 hour per day on electronics?

○ 0.22
○ 0.25
○ 0.70
○ 0.88

Explanation:

Step1: Identify conditional probability set

We focus on children who spend at least 1 hr/day outside. The total number of such children is 16, and the number of these children who spend less than 1 hr/day on electronics is 14.

Step2: Calculate conditional probability

Conditional probability formula: $P(A|B)=\frac{\text{Number of } A \cap B}{\text{Number of } B}$
Substitute values: $\frac{14}{16}$

Step3: Simplify and round

$\frac{14}{16}=0.875$, rounded to nearest hundredth is $0.88$.

Answer:

0.88