Chocolate bars produced by a certain machine are labeled with 8.0 oz. The distribution of the acutal weights of these chocolates bars is Normal with a mean of 8.1 oz and a standard deviation of 0.1oz. A chocolate bar is considered underweight if it weighs less then 8.0 oz.

(A) What proportion of chocolate bars wieghs less then 8.0 oz?
(B) What propertion of chocolate bars weighs between 8.2 and 8.3 oz?
(C) How should the chocolate bar wrappers be labeled so that only 1% of such bars are underwight?

Step-by-step explanation:

a. Let C be the normally distributed random variable.

-Given the chocolates is normally distributed with mean =8.1 oz and standard deviation =0.1 oz.

#The proportion of those less than 8.0 oz can be calculated as:

Hence, the proportion of bars weighing below 8 ounces is 0.1587 or 15.87%

b. We use the z-test to determine the probability or proportion of bars weighing between 8.2 and 8.3 ounces:

Hence, the proportion of bars weighing between 8.2 and 8.3 ounces is 0.1359 or 13.59%

c. To label the wrappers such that only 1% are underweight.

#Find B such that

P(C<B)=0.01

#Now find z-value such that:

Using the z-tables, z=-2.33

Therefore:

Hence, the wrappers should be labelled as 7.87 ounces

The length of the rectangular delivery box must be equal to 4 inches.

Let the length of the box be L.

Let the width of the box be W.

Let the height of the box be H.

Given the following data:

Translating the word problem into an algebraic expression;

 ......equation 1

 ......equation 2.

Mathematically, the volume of a rectangular solid is given by the formula;

 .....equation 3.

Substituting the values into equation, we have;

Rearranging the polynomial, we have;

We would apply the remainder theorem to solve the polynomial.

According to the remainder theorem, if a polynomial P(x) is divided by (x - r) and there is a remainder R; then P(r) = R.

When x = 3

We would try with 4;

Therefore, 4 is one of its roots.

Hence, the length of the rectangular delivery box must be equal to 4 inches.

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