University of Southeastern Philippines
eBA 201 Managerial Statistics
Exercise 3
Name: Nathan Kit A. Berro
1.(50 points)The following data represent the life (in Hours) of a sample of 40 100-watt light
bulbs produced by ABC Manufacturing.
Life (in hours) Number of Bulbs
1,050 – 1149 4
950 – 1049 8
850 – 949 20
750 – 849 3
650 – 749 5
Midpoint
Cumulative
Class Interval Class Boundaries Frequency(f) of fm
Frequency
Class(m)
1,050-1,149 1,049.5-1,050.5 4 1,099.5 4,398 40
950-1,049 949.5-1,049.5 8 999.5 7,996 36
850-949 849.5-949.5 20 899.5 17,990 28
750-849 749.5-849.5 3 799.5 2,398.5 8
650-749 649.5-749.5 5 699.5 3,497.5 5
Total 40 36,280
a. Compute for the mean, median and mode
a.1 Mean = 907
mean = ΣƒiXi/n
= 36,
= 907
a.2 median = 909.5
Σƒi /2 = = 20 which is contained by 28, the cumulative frequency of the class interval
850-949. Therefore, the median class is 850-949.
Lower boundary (L) = 849.5
eBA 201 Managerial Statistics
Exercise 3
Name: Nathan Kit A. Berro
1.(50 points)The following data represent the life (in Hours) of a sample of 40 100-watt light
bulbs produced by ABC Manufacturing.
Life (in hours) Number of Bulbs
1,050 – 1149 4
950 – 1049 8
850 – 949 20
750 – 849 3
650 – 749 5
Midpoint
Cumulative
Class Interval Class Boundaries Frequency(f) of fm
Frequency
Class(m)
1,050-1,149 1,049.5-1,050.5 4 1,099.5 4,398 40
950-1,049 949.5-1,049.5 8 999.5 7,996 36
850-949 849.5-949.5 20 899.5 17,990 28
750-849 749.5-849.5 3 799.5 2,398.5 8
650-749 649.5-749.5 5 699.5 3,497.5 5
Total 40 36,280
a. Compute for the mean, median and mode
a.1 Mean = 907
mean = ΣƒiXi/n
= 36,
= 907
a.2 median = 909.5
Σƒi /2 = = 20 which is contained by 28, the cumulative frequency of the class interval
850-949. Therefore, the median class is 850-949.
Lower boundary (L) = 849.5
