Question

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 relevant values

We want the probability that a child spends less than 1 - hour per day on electronics given they spend at least 1 hour per day outside. The number of children who spend at least 1 hour per day outside and less than 1 hour per day on electronics is 14, and the total number of children who spend at least 1 hour per day outside is 16.

Step2: Calculate probability

The formula for conditional - probability in this case is $P(A|B)=\frac{n(A\cap B)}{n(B)}$, where $A$ is the event of spending less than 1 hour per day on electronics and $B$ is the event of spending at least 1 hour per day outside. So the probability $P=\frac{14}{16}=\frac{7}{8} = 0.875\approx0.88$.

Answer:

0.88