(a) Explain whyXis a binomial random variable.

(b) Find and interpret the expected value ofX.

(c) Find and interpret the standard deviation ofX.

Short Answer

Expert verified

(a) Variablexhas all the required conditions for a binomial distribution Thus, the variable xis a binomial random variable.

(b) Expected value of is 1.60

(c) Standard deviation of Xis1.1314

Step by step solution

01

Part (a) Step 1: Given information

Given in the question that, According to the Mars candy company, 20%of its plain M&M’s candies are orange. Assume that the company’s claim is true. Suppose that you reach into a large bag of plain M&M’s (without looking) and pull out 8candies.

02

Part (a) Step 2: Explanation

Probability of success (p)localid="1649747575227" =20%=0.20.

Number of trials localid="1649747578779" (n)=8

The random variable X, which is a binomial random variable, is as follows:

  • There are two types of successes and failures: orange candy and non-orange candy.
  • The candies are kept apart from one another.
  • The number of candies is predetermined.
  • The likelihood of receiving orange candy is set.

Because all of the requirements for a binomial distribution are predetermined. As a result, the variable Xis a random variable with a binomial distribution.

03

Part (b) Step 1: Given information

Given in the question that, According to the Mars candy company, 20%of its plain M&M’s candies are orange. Assume that the company’s claim is true. Suppose that you reach into a large bag of plain M&M’s (without looking) and pull out 8
candies. Let X= the number of orange candies you get. We need to find and interpret the expected value of X.

04

Part (b) Step 2: Explanation

The mean can be calculated as:

μ=n×p

=8(0.20)

=1.60

The above computed mean shows that the expected number of candies is 1 .

05

Part (c) Step 1: Given information

Given in the question that, According to the Mars candy company, 20%of its plain M&M’s candies are orange. Assume that the company’s claim is true. Suppose that you reach into a large bag of plain M&M’s (without looking) and pull out 8candies. Let X= the number of orange candies you get. We need to find and interpret the standard deviation of X.

06

Part (c) Step 2: Explanation

The standard deviation can be calculated as:

σ=n×p×(1p)

=8(0.20)(10.20)

=1.1314

The above-computed mean indicates that the number of candies will vary by 1.1314by the average of 1.60candies.

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