Names: Fernandez, Roiden Fredrich Section: IX- Krypton Sundo, Christine Kate Subject: Math9a Tanacio, Shekinah Teacher: Lester Lou Segumpan Tayong, Cryschia Faye Date: July 6, 2014

The following are data on the observed number of home appliances of 60 samples of Grade 7 Topaz CMULHS Students.

Number ofTally

Class BoundariesClass Mark <cf >cf fx fx²Appliances LB UB

61 - 70 2 60.5 70.5 65.5 60 2 131 8580.551 - 60 0 50.5 60.5 55.5 58 2 0 041 - 50 2 40.5 50.5 45.5 58 4 91 4140.531 - 40 4 30.5 40.5 35.5 56 8 142 504121 - 30 5 20.5 30.5 25.5 52 13 127.5 3251.2511 - 20 19 10.5 20.5 15.5 47 32 294.5 4564.751 - 10 28 0.5 10.5 5.5 28 60 154 847

c=10 n=60 ∑fx=940 ∑fx²=26425

Solutions:

R = 70-2= 68

m = 1 + 3.3 log 60 = 6.86= 7 classes

c = 68/7 = 9.71

Use c= 10 since the data values are nearest ones.

The lowest value is 2. It is convenient to start with 1 as the lower limit of the 7th class.

Measures of Central Tendency

1. Mean

2. Median

To find median class, we need

x=∑ fx

n

x=94060

x=15.66

~x=L+( n2−Ff m )C~x=20.5+( 30−475 )10

MedianClass=n2

MedianClass=602

MedianClass=30

~x=20.5+(−175 )10~x=20.5+ (−3.4 )10

~x=20.5−34

~x=−13.5

3. Mode

To identify the modal class, choose the class with the highest frequency:

The Modal Class is the class 1-10 because it has the highest frequency.

x=L+¿

x=0.5+( 28−02 (28 )−0−19 )10

x=0.5+( 2856−19 )10

x=0.5+( 2837 )10

x=0.5+ (0.756 )10

x=0.5+ (0.76 )10

x=0.5+7.6

x=8.1

Measures of Variation

1. Range

2. Variance

3. Standard Deviation

R=UBu−LBl

R=70.5−0.5

R=70

s2=n∑−¿¿¿

s2=60 (26425 )−(940) ²

60 (60−1 )

s2=1585500−883,60060 (59 )

s2=7019003540

s2=198.2768362

s2=198.28

s=14.08108079

s=√❑

s=√198.2768362

s=14.08