find third proportional to 1.6 and 14.4
Answers
Part 1:
Let the mean proportional between 14.4 and 3.6 = b
=> b² = 14.4 * 3.6
=> b² = 144*36/10*10
=> b = 12*6/10
=> b = 36/5
Part 2:
Let the third proportional of 5 and 4 = c
=> 4² = 5*c
=> c = 16/5
The required ratio is
= 36/16
= 9/4
= 9:4
The ratio of the mean proportional between 14.4 and 3.6 and the third proportional of 5 and 4 is 9:4
Remember:
If a, b and c are in continued proportion,
a is the first proportional
b is the mean proportional
c is the third proportional
If a, b and c are in continued proportion, it is denoted as:
=>
=> b² = ac
Answer:
Let the mean proportional between 14.4 and 3.6 = b
=> b² = 14.4 * 3.6
=> b² = 144*36/10*10
=> b = 12*6/10
=> b = 36/5
Let the third proportional of 5 and 4 = c
=> 4² = 5*c
=> c = 16/5
The required ratio is 516536
= 36/16
= 9/4
= 9:4
The ratio of the mean proportional between 14.4 and 3.6 and the third proportional of 5 and 4 is 9:4
Remember:
If a, b and c are in continued proportion,
a is the first proportional
b is the mean proportional
c is the third proportional
If a, b and c are in continued proportion, it is denoted as:
=>
=> b² = ac