Math Problem Statement

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Part 1

In a certain​ country, the true probability of a baby being a

girlgirl

is

0.4810.481.

Among the next

fourfour

randomly selected births in the​ country, what is the probability that at least one of them is a

boyboy​?

Question content area bottom

Part 1

The probability is

enter your response here.

​(Round to three decimal places as​ needed.)

Solution

We are given the probability of a baby being a girl as P(girl)=0.481P(\text{girl}) = 0.481.

The probability of a baby being a boy is then: P(boy)=1P(girl)=10.481=0.519P(\text{boy}) = 1 - P(\text{girl}) = 1 - 0.481 = 0.519

We are asked to find the probability that at least one of the next four randomly selected births is a boy.

Step 1: Approach using Complementary Probability

The easiest way to solve this is to use complementary probability. Instead of directly finding the probability of at least one boy, we can calculate the probability of the complementary event (i.e., no boys at all), and subtract this from 1.

  • The probability of no boys (i.e., all four babies are girls) is: P(no boys)=P(girl)4=0.4814P(\text{no boys}) = P(\text{girl})^4 = 0.481^4

  • The probability of at least one boy is then: P(at least one boy)=1P(no boys)=10.4814P(\text{at least one boy}) = 1 - P(\text{no boys}) = 1 - 0.481^4

Step 2: Calculation

Now we will calculate 0.48140.481^4 and subtract it from 1 to get the desired probability.

0.48140.05420.481^4 \approx 0.0542 P(at least one boy)=10.0542=0.9458P(\text{at least one boy}) = 1 - 0.0542 = 0.9458

Final Answer:

The probability that at least one of the four babies is a boy is approximately 0.946 (rounded to three decimal places).


Would you like further clarification on the steps, or do you have another question?

Here are 5 related questions you might find interesting:

  1. What is the probability that all four babies are girls?
  2. If the probability of a boy were 0.6, how would this affect the calculation?
  3. How do complementary probabilities work in other real-life scenarios?
  4. What is the formula for binomial probability and how does it apply to this question?
  5. How would you adjust this calculation if there were more or fewer babies?

Tip: Remember, complement probability is often useful in situations where calculating the desired outcome directly is complex!

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Math Problem Analysis

Mathematical Concepts

Probability
Complementary Probability
Binomial Probability

Formulas

P(boy) = 1 - P(girl)
P(at least one boy) = 1 - P(no boys)
P(no boys) = P(girl)^4

Theorems

Complementary Probability Theorem

Suitable Grade Level

Grades 7-9