Question

. The mean width of 12 iPads is 5.1 inches. The mean width of 8 Kindles is 4.8 inches. a. What is the total width of the iPads? b. What is the total width of the Kindles? c. What is the mean width of the 12 iPads and 8 Kindles?

Answer 1

Answer:

a) 61.2, b) 38.4 and c) 4.98

Step-by-step explanation:

Given:

The mean width of 12 I-Pads is 5.1 inches.

The mean width of 8 Kindles is 4.8 inches.

Question asked:

a. What is the total width of the I-Pads?

b. What is the total width of the Kindles?

c. What is the mean width of the 12 I-Pads and 8 Kindles?

Solution:

As we know:

$Mean =\frac{Sum\ of\ observations}{Number\ of\ observations}\\ \\ Mean\ width =\frac{Sum\ of\ width\ of\ all \ I-pad}{Number \ of\ I-pad}$

$5.1=\frac{Sum\ of\ width\ of\ all\ I-pad}{12} \\ \\ By \ cross\ multiplication\\ \\ Sum\ of\ width\ of\ all\ I-pad}=5.1\times1 2\\ \\ Sum\ of\ width\ of\ all\ I-pad}= 61.2$

a) Thus, the total width of the I-Pads are 61.2 inches.

$Mean\ width =\frac{Sum\ of\ width\ of\ all\ Kindles}{Number \ of\ Kindles}$

$4.8=\frac{Sum\ of\ width\ of\ all\Kindles}{8} \\ \\ By \ cross\ multiplication\\ \\ Sum\ of\ width\ of\ all \ Kindles=4.8\times8\\ \\ Sum\ of\ width\ of \ all\ Kindles}=38.4$

b) Thus, total width of the Kindles are 38.4 inches.

Combined width of both I-pad and Kindles = 61.2 + 38.4 = 99.6 inches

Combined number of observations = 12 + 8 =20

Combined mean of width of the 12 I-Pads and 8 Kindles = Combined width of both I-pad and Kindles $\div$ Combined number of observations

Combined mean of width of the 12 I-Pads and 8 Kindles = $\frac{99.6}{20} =4.98\ inches$

c) Thus, the mean width of the 12 I-Pads and 8 Kindles is 4.98 inches.