Question

a survey of 250 people found that 163 people own a phone, 45 own a laptop, and 21 own both. what is the probability that a randomly selected person owns a laptop or a phone?

\\(p(\text{laptop or phone}) = ?\\%\\)

round your answer to the nearest whole percent.

Explanation:

Define the given values

Using the Theoretical Probability knowledge point

$$
LATEXBLOCK0
$$

Apply the Addition Rule for Probability

Since owning a phone and owning a laptop are not Mutually Exclusive Events, we use the general addition rule:

$$ n(P \cup L) = n(P) + n(L) - n(P \cap L) $$

$$ n(P \cup L) = 163 + 45 - 21 = 187 $$

Calculate the probability

Using the Theoretical Probability knowledge point

$$ P(P \cup L) = \frac{n(P \cup L)}{N} = \frac{187}{250} = 0.748 $$

Convert to percentage and round

$$ 0.748 \times 100\% = 74.8\% \approx 75\% $$

Answer:

A survey of 250 people found that 163 people own a phone, 45 own a laptop, and 21 own both. What is the probability that a randomly selected person owns a laptop or a phone?

\(P(\text{Laptop or Phone}) =\) <blank>75</blank>%

Round your answer to the nearest whole percent.