Question

The weights of red delicious apples are approximately normally distributed with a mean of 9 Ounces and a standard deviation of 0.75 ounce. An online gift store sells gift boxes containing delicious apples. At the time of packaging. 5 red delicious apples are randomly selected and packaged in a box. red a. Describe the distribution of the total weight of the 5 randomly selected apples. b. What is the probability that the total weight of the 5 randomly selected apples will be less than 42 ounces? c. The combined weight of the packing material and box in which the apples will be shipped is always 10 ounces. Let W represent the weight of a complete packaged gift box, which consists of the packing material, box, and 5 randomly selected apples. What are the mean and the standard deviation of W?

Answer 1

Answer:

The mean of W is 55 ounces.

The standard deviation of W is 4.33 ounces.

Step-by-step explanation:

Let X: weight of a red delicious apple, and B: the weight of the box and packing material.

The distribution that will represent W: the total weight of the packaged 5 randomly selected apples will be also normally distributed.

Applying the property of the mean: $E(aX)=aE(X)$, the mean of W will be:

$\mu_W=E(W)=E(5X+B)=5E(X)+E(B)=5*9+10=45+10=55$

Applying the property of the variance: $V(aX+b)=a^2V(X)$, the variance of W will be:

$\sigma^2_W=V(W)=V(5X+B)=5^2V(X)+V(B)=25*0.75+0=18.75$

The mean standard deviation of W will be the squared root of V(W):

$\sigma_W=\sqrt{V(W)}=\sqrt{18.75}=4.33$

The mean of W is 55 ounces.

The standard deviation of W is 4.33 ounces.