8)The mean height of 50students is 5’8’’. The height of 10students is given below. 5’6’’,5’2’’, 5’4”,5’0’’, 4’10’’,4’8’’,6’2’’,5’8’’,5’9’’,5’3’’. Find the mean height of the remaining 40 students.
Answers
Answer:
Answer = 5'9"
Step-by-step explanation:
Mean Height of 50 students = 5'8"
Height of 10 students: 5'6" ,5'2" ,5'4" , 5'0" ,4'10" ,4'8" ,6'2" ,5'8" ,5'9" ,5'3"
1 feet=12 inches
Now, convert height of 10 students in inches
5'6" = 5×12+6 = 66 inches
5'2" = 5×12+2 = 62 inches
5'4" = 5×12+4 = 64 inches
5'0" = 5×12+0 = 60 inches
4'10" = 4×12+10 = 58 inches
4'8" = 4×12+8 = 56 inches
6'2" = 6×12+2 = 74 inches
5'8" = 5×12+8 = 68 inches
5'9" = 5×12+9 = 69 inches
5'3" = 5×12+3 = 63 inches
Sum of height of 10 students = 66+62+64+60+58+56+74+68+69+63
= 640
Let sum of observations of remaining 40 students be x.
Mean of 50 students = 5'8" = 5×12+8 = 68
Mean = sum of observations/total number of observations
Mean of 50 students = sum of height of 40 students + 10 students/50
⇒ 68 = x + 640/50
⇒ 68×50 = x + 640
⇒ 3400 = x + 640
⇒ 3400 - 640 = x
⇒ 2760 = x
⇒ x = 2760
Sum of height of 40 students = 2760
Mean height of 40 students = 2760/40
= 69
Mean height of 40 students = 69 inches
= 69÷12 feet = 5'9"