Question

Find a . the mean ; b . the deviation from the mean for each data item ; and c . the sum of the deviations in part ( b ) for the following group of data items . 155 , 156 , 162 , 164 , 168

Answer 1

(a) The mean of the data item from the group data is 161.

(b) The deviation from the mean for each data is -6,-5,1,3 and 7. respectively.

(c) The sum of the deviation is 0

What is a group data?

Grouped data are data formed by aggregating individual observations of a variable into groups, so that a frequency distribution of these groups serves as a convenient means of summarizing or analyzing the data.

(a) To find the mean of the data, we use the formula below.

Formula:

• M = ∑x/n.......... Equation 1

Where:

• M = Mean = ?
• ∑x = Sum of each data = 155+156+162+164+168 = 805
• n = Total number of data item = 5

Substitute these values into equation 1

• M = 805/5
• M = 161

(b) To calculate the deviation from the mean (M') for each of the data item we use the formula below.

M' = x-M

For data 115,

• M' = 155-161 = -6

For data 156,

• M' = -5

For data 162,

• M' = 162-161 = 1

For data 164,

• M' = 164-161
• M' = 3

For data 168,

• M' = 168-161
• M' = 7

(c) The sum of the deviation is

• ∑M' = -6+(-5)+1+3+7
• ∑M'  = 0

Hence, the mean, the diaviation from the mean is -6,-5,1,3 and 7  and the sum of the deviation of the data is 161 and 0 respectively,

Learn more about group data here: brainly.com/question/24298037

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