Question

The Computer Club at Highlands Middle School has 6th graders, 7th graders, and 8th graders among its 40 members. The probability model for choosing a club member is given If a club member is chosen at random, what is the probability that he or she will not be a 7th grader?

Answer 1

To determine the probability that a randomly chosen member of the Computer Club at Highlands Middle School is not a 7th grader, we first need to know how many members are in each grade (6th, 7th, and 8th) or at least the number of 7th graders.

However, since that information isn’t provided, we can analyze the situation using general notation. Let's define:

- \( n_6 \): the number of 6th graders
- \( n_7 \): the number of 7th graders
- \( n_8 \): the number of 8th graders

According to the problem, the total number of members in the club is:

\[
n_6 + n_7 + n_8 = 40
\]

To find the probability that a randomly chosen member is not a 7th grader, we can use the complement of the probability of choosing a 7th grader.

The probability of choosing a 7th grader is:

\[
P(7th \text{ grader}) = \frac{n_7}{40}
\]

Then, the probability of not choosing a 7th grader is:

\[
P(\text{not } 7th \text{ grader}) = 1 - P(7th \text{ grader}) = 1 - \frac{n_7}{40}
\]

This simplifies to:

\[
P(\text{not } 7th \text{ grader}) = \frac{40 - n_7}{40}
\]

To provide a specific numerical result for this probability, we would need to know the actual number of 7th graders \( n_7 \).

In summary, the formula for the probability that a randomly chosen club member is not a 7th grader is:

\[
P(\text{not } 7th \text{ grader}) = \frac{40 - n_7}{40}
\]

If you can provide the number of 7th graders, I can give you a specific numerical probability.