Ten experts rated a newly developed chocolate chip cookie on a scale of 1 to 50. Their ratings were:
34, 35, 41, 28, 26, 29, 32, 36, 38, and 40.
1. What is the mean deviation of the ratings?
Select one:
a. 8.00
b. 4.12
c. 12.67
d. 0.75

Respuesta :

Answer:

Option B.

Step-by-step explanation:

The given data set is

34, 35, 41, 28, 26, 29, 32, 36, 38, 40

We need to find the mean deviation of the given data.

Number of observations, n = 10

Mean of the data is

[tex]Mean=\dfrac{\sum x}{n}[/tex]

[tex]Mean=\dfrac{34+35+41+28+26+29+32+36+38+40}{10}[/tex]

[tex]Mean=\dfrac{339}{10}[/tex]

[tex]Mean=33.9[/tex]

Formula for mean deviation is

[tex]\text{Mean deviation}=\dfrac{\sum |x-mean|}{n}[/tex]

[tex]\sum |x-mean|=|34-33.9|+|35-33.9|+|41-33.9|+|28-33.9|+|26-33.9|+|29-33.9|+ |32-33.9|+|36-33.9|+|38-33.9|+|40-33.9|=41.2[/tex]

[tex]\text{Mean deviation}=\dfrac{41.2}{10}[/tex]

[tex]\text{Mean deviation}=4.12[/tex]

The mean deviation of the ratings is 4.12.

Therefore, the correct option is B.

Answer:

b. 4.12

Step-by-step explanation:

We have been given that 10 experts rated a newly developed chocolate chip cookie on a scale of 1 to 50. Their ratings were:

34, 35, 41, 28, 26, 29, 32, 36, 38, and 40.

First of all, we will find the mean of the ratings.

[tex]\text{Mean of ratings}=\frac{34+35+41+28+26+29+32+36+38+40}{10}[/tex]

[tex]\text{Mean of ratings}=\frac{339}{10}[/tex]

[tex]\text{Mean of ratings}=33.9[/tex]

Let us find absolute deviation of each point from mean.

[tex]|34-33.9|=0.1[/tex]

[tex]|35-33.9|=1.1[/tex]

[tex]|41-33.9|=7.1[/tex]

[tex]|28-33.9|=5.9[/tex]

[tex]|26-33.9|=7.9[/tex]

[tex]|29-33.9|=4.9[/tex]

[tex]|32-33.9|=1.9[/tex]

[tex]|36-33.9|=2.1[/tex]

[tex]|38-33.9|=4.1[/tex]

[tex]|40-33.9|=6.1[/tex]

Now we will use mean deviation formula.

[tex]\text{Absolute mean deviation}=\frac{\Sigma |x-\mu|}{N}[/tex], where,

[tex]\mu=\text{Mean}[/tex] and N = Number of data points.

[tex]MD=\frac{0.1+1.1+7.1+5.9+7.9+4.9+1.9+2.1+4.1+6.1}{10}[/tex]

[tex]MD=\frac{41.2}{10}[/tex]

[tex]MD=4.12[/tex]

Therefore, the mean deviation of the ratings is 4.12 and option 'b' is the correct choice.