Mean Deviation, Variance and standard Deviation of Grouped Data use in solving practical problems related to real life situations

EVALUATION

1. Calculate to 1 d.p the mean and standard deviation of the following numbers:
   1. 5, 7, 12, 10, 5, 15, 14, 9, 7, 8
   1. 6.5, 8.5, 6.5, 8.4, 6.9, 2.5, 6.2, 5.5

GENERAL EVALUATION

1. The table bellows shows the age distributions of a group of people.

Age (yrs)	20 – 29	30 – 39	40 – 49	50 – 59	60 – 69	70 – 79
Frequency	3	5	10	13	7	2

Calculate:

• The mean age
  • The variance
  • The standard deviation

READING ASSIGNMENT

Essential Mathematics for Senior Secondary 1 pgs 237 – 248

WEEKEND ASSIGNMENT

1. The lowest temperatures of a city in Asia for 10 consecutive days are recorded as: – 5^oC, – 6^oC, -5^oC, 4^oC, 0^oC, 1^oC, 2^oC, 3^oC, 4^oC, 7^oC. Find the mean deviation.    A. 3.9     B. 4.0     C. 3.6      D. 6.4

Use the table below to answer question 2 to 4

A dice is thrown 100 times. The results are recorded as shown in the following table

Score	1	2	3	4	5	6
Frequency	15	18	17	21	14	15

Calculate:

• The mean score    A. 4.0     B. 3.5      C. 1.0       D. 5.6
• The variance    A. 2.7      B. 3.7       C. 2.1        D. 1
• The standard deviation     A. 4       B. 5.1       C. 1.6       D. 7
• Find the variance of x, 2x, 3x, 4x, 5x, 6x, 7x, 8x, 9x and 10x.    A. 8.25x²9x²     B. 10x²     7.25x²

THEORY

1. The shoe sizes of a group of people are as follows:

Shoe size	5	6	7	8	9	10	11	12	13
Frequency	3	8	14	16	20	10	5	3	1

For this distribution, calculate the mean deviation

• The table below show the age distributions of a group of people.

Age (yrs)	20 – 29	30 – 39	40 – 49	50 – 59	60 -69	70 – 79
Frequency	3	5	10	13	7	2

Calculate (a) the mean age    (b) the variance    (c) the standard deviation