Math Problem Statement

The prices paid for a particular model of OLED television is normally distributed with a mean price of $1500 and a standard deviation of $95.

Use this information to fill in the blanks and answer the questions. Round probabilities to four decimal places.

a. What is the probability that a randomly selected buyer paid more than $1700?

b. What is the probability that a randomly selected buyer paid between $1400 and $1600?

c. What is the probability that a randomly selected buyer paid less than $1350?

Solution

The problem states that the prices paid for a particular OLED television are normally distributed with a mean of $1500 and a standard deviation of $95. We will use the standard normal distribution (Z-distribution) to calculate the probabilities for each of the scenarios. For this, we will convert the prices into Z-scores using the formula:

Z=XμσZ = \frac{X - \mu}{\sigma}

Where:

  • XX is the price,
  • μ=1500\mu = 1500 (mean),
  • σ=95\sigma = 95 (standard deviation).

(a) Probability that a randomly selected buyer paid more than $1700:

  1. First, calculate the Z-score for X=1700X = 1700:

Z=1700150095=200952.1053Z = \frac{1700 - 1500}{95} = \frac{200}{95} \approx 2.1053

  1. Using a standard normal distribution table or a calculator, find the probability that Z>2.1053Z > 2.1053. The area to the left of Z=2.1053Z = 2.1053 is approximately 0.9824. Therefore, the probability of paying more than $1700 is:

P(X>1700)=10.9824=0.0176P(X > 1700) = 1 - 0.9824 = 0.0176

So, the probability is approximately 0.0176.


(b) Probability that a randomly selected buyer paid between $1400 and $1600:

  1. Calculate the Z-score for X=1400X = 1400:

Z=1400150095=100951.0526Z = \frac{1400 - 1500}{95} = \frac{-100}{95} \approx -1.0526

  1. Calculate the Z-score for X=1600X = 1600:

Z=1600150095=100951.0526Z = \frac{1600 - 1500}{95} = \frac{100}{95} \approx 1.0526

  1. Find the probabilities corresponding to these Z-scores:

    • For Z=1.0526Z = -1.0526, the area to the left is approximately 0.1462.
    • For Z=1.0526Z = 1.0526, the area to the left is approximately 0.8538.
  2. The probability that a buyer paid between $1400 and $1600 is the difference between these two probabilities:

P(1400<X<1600)=0.85380.1462=0.7076P(1400 < X < 1600) = 0.8538 - 0.1462 = 0.7076

So, the probability is approximately 0.7076.


(c) Probability that a randomly selected buyer paid less than $1350:

  1. Calculate the Z-score for X=1350X = 1350:

Z=1350150095=150951.5789Z = \frac{1350 - 1500}{95} = \frac{-150}{95} \approx -1.5789

  1. Using a standard normal distribution table or a calculator, find the probability corresponding to Z=1.5789Z = -1.5789. The area to the left of this Z-score is approximately 0.0572.

Therefore, the probability that a buyer paid less than $1350 is approximately 0.0572.


Summary of Answers:

  • (a) The probability that a randomly selected buyer paid more than $1700 is 0.0176.
  • (b) The probability that a randomly selected buyer paid between $1400 and $1600 is 0.7076.
  • (c) The probability that a randomly selected buyer paid less than $1350 is 0.0572.

Would you like more details or have any questions on this?

Related Questions:

  1. What is the probability that a buyer paid between $1300 and $1700?
  2. What is the price at which 90% of the buyers paid more?
  3. What is the probability that a buyer paid exactly the mean price?
  4. If you were to randomly select 10 buyers, what is the probability that exactly one of them paid more than $1700?
  5. What price would correspond to the 95th percentile of the distribution?

Tip:

In normal distribution problems, converting raw scores to Z-scores allows you to use standard tables or calculators for probabilities, simplifying the process!

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Math Problem Analysis

Mathematical Concepts

Normal Distribution
Z-Score
Probability

Formulas

Z = (X - μ) / σ
P(X > 1700) = 1 - P(Z ≤ Z_1700)
P(1400 < X < 1600) = P(Z ≤ Z_1600) - P(Z ≤ Z_1400)
P(X < 1350) = P(Z ≤ Z_1350)

Theorems

Standard Normal Distribution

Suitable Grade Level

Grades 10-12