Question
upstudy study bank question image url

\( 26 \% \) of college students say they use credit cards because of the rewards program. You randomly select 10 college students and ask each to name the reason he or she uses credit cards. Find the probability that the number of college students who say they use credit cards because of the rewards program is (a) exactly two, (b) more than two, and (c) between two and five inclusive. If convenient, use technology to find the probabilities. (a) \( \mathrm{P}(2)=0.274 \) (Round to the nearest thousandth as needed.) (b) \( \mathrm{P}(\mathrm{x}>2)=0.503 \) (Round to the nearest thousandth as needed.) (c) \( \mathrm{P}(2 \leq x \leq 5)=\square \) (Round to the nearest thousandth as needed.)

Ask by Ward Medina. in the United States
Jan 21,2025

Real Tutor Solution

Tutor-Verified Answer

Answer

The probability that between two and five college students use credit cards because of rewards is 0.753.

Solution

To solve part (c) of the problem, we need to find the probability that the number of college students who say they use credit cards because of the rewards program is **between two and five inclusive**. Given: - Probability of a student using a credit card for rewards (\( p \)) = 26% or 0.26 - Number of students selected (\( n \)) = 10 - We are dealing with a **binomial distribution** since each trial (student) is independent and has two possible outcomes (uses credit cards for rewards or not). ### Part (c): \( \mathrm{P}(2 \leq x \leq 5) \) We need to calculate: \[ \mathrm{P}(2 \leq X \leq 5) = \mathrm{P}(X=2) + \mathrm{P}(X=3) + \mathrm{P}(X=4) + \mathrm{P}(X=5) \] Given that parts (a) and (b) have already provided: - \( \mathrm{P}(X=2) = 0.274 \) - \( \mathrm{P}(X>2) = 0.503 \) However, to ensure accuracy, let's calculate each probability individually using the binomial probability formula: \[ \mathrm{P}(X=k) = \binom{n}{k} p^k (1-p)^{n-k} \] where \( \binom{n}{k} \) is the binomial coefficient. #### 1. \( \mathrm{P}(X=2) \) \[ \mathrm{P}(X=2) = \binom{10}{2} (0.26)^2 (0.74)^8 \approx 0.274 \] #### 2. \( \mathrm{P}(X=3) \) \[ \mathrm{P}(X=3) = \binom{10}{3} (0.26)^3 (0.74)^7 \approx 0.256 \] #### 3. \( \mathrm{P}(X=4) \) \[ \mathrm{P}(X=4) = \binom{10}{4} (0.26)^4 (0.74)^6 \approx 0.157 \] #### 4. \( \mathrm{P}(X=5) \) \[ \mathrm{P}(X=5) = \binom{10}{5} (0.26)^5 (0.74)^5 \approx 0.066 \] ### Summing Up the Probabilities \[ \mathrm{P}(2 \leq X \leq 5) = 0.274 + 0.256 + 0.157 + 0.066 = 0.753 \] **Final Answer:** \[ \mathrm{P}(2 \leq X \leq 5) = 0.753 \] Rounded to the nearest thousandth, the probability is **0.753**.

Reviewed and approved by the UpStudy tutoring team

error msg
Explain
Simplify this solution

Bonus Knowledge

To solve this problem, we can model the situation using the binomial probability formula since we have a fixed number of trials (10 college students), two possible outcomes (using credit cards for rewards or not), and a constant probability of success (26% or 0.26). First, let’s note the formula for finding the probability of exactly \( k \) successes in \( n \) trials: \[ P(X = k) = \binom{n}{k} p^k (1-p)^{n-k} \] Where: - \( \binom{n}{k} \) is the binomial coefficient, - \( n \) is the number of trials, - \( k \) is the number of successes, - \( p \) is the probability of success, and - \( (1-p) \) is the probability of failure. Given: - \( n = 10 \) - \( p = 0.26 \) (a) For \( P(X = 2) \): \[ P(X = 2) = \binom{10}{2} (0.26)^2 (0.74)^{8} \] Calculating this we get: \[ = \frac{10!}{2!(10-2)!} \cdot (0.26)^2 \cdot (0.74)^{8} \approx 0.274 \] (b) For \( P(X > 2) \): This can be computed as \( 1 - P(X \leq 2) \) which is \( 1 - [P(X = 0) + P(X = 1) + P(X = 2)] \). Calculating each separately: - \( P(X = 0) \approx 0.062 \) - \( P(X = 1) \approx 0.187 \) - \( P(X = 2) \approx 0.274 \) Thus, \[ P(X \leq 2) = P(X = 0) + P(X = 1) + P(X = 2) \approx 0.062 + 0.187 + 0.274 \approx 0.523 \] So, \[ P(X > 2) \approx 1 - 0.523 \approx 0.477 \] (c) For \( P(2 \leq X \leq 5) \): This is calculated as \( P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) \). Calculating \( P(X = 3), P(X = 4), \) and \( P(X = 5) \): Using the formula: - \( P(X = 3) \approx 0.227 \) - \( P(X = 4) \approx 0.137 \) - \( P(X = 5) \approx 0.062 \) Adding them together: \[ P(2 \leq X \leq 5) = P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) \approx 0.274 + 0.227 + 0.137 + 0.062 \approx 0.700 \] So the final results (rounded to the nearest thousandth) are: **(a)** \( P(2) = 0.274 \) **(b)** \( P(X > 2) = 0.477 \) (Corrected from earlier, make sure to feed this into your tech tools for verification!) **(c)** \( P(2 \leq X \leq 5) \approx 0.700 \) (Round to the nearest thousandth as needed.)

Related Questions

Latest Probability Questions

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy