Continued or Mean Proportion

Q. If 25, 35, and x are in continued proportion, then find the value of x.

Q.

Find the mean of the first 10 multiples of 2.

1. 11

2. 10

3. 12

4. 9

Q.

The average age of three boys is $15years$ and their ages are in proportion$3:5:7$. What is the age in years of the youngest boy?

Q.

Determine if 200 ml:2.5 liters and 4:50 ratios form a proportion.

1. No

2. Yes

Q.

Find the mean proportion between $\frac{1}{4}$ and $\frac{1}{9}$

1. 6

2. 0.36

3. $\frac{1}{6}$

4. $\frac{1}{36}$

Q.

If $a:b=b:c$, then $b$ is called the mean proportional between $a$ and $c$; and $a,b,c$are said to be in proportion.

Are the given numbers in proportion: $2,4,8$

Q.

Find the fourth proportional of 14 , 7 and 10

1. 7

2. 10

3. 5

4. 6

Q.

Find the third proportion to $4\frac{1}{6}$, $5$.

Q.

If the ratios formned using the numbers 6, $x$, 25 , 75 in the same order are in proportion, then '$x$' is ___

1. 18

2. 50

3. 24

4. 5

Q.

Find the missing term $9,17,19,27,29,\_\_\_,39$.

1. $37$

2. $37.5$

3. $38$

4. $38.5$

Q.

What number must be added to each of the numbers $5,11,19,37$ so they are in proportion ?

Q.

Draw a line segment of length $7.6cm$and divide it in the ratio $5:8$. Measure the two parts. Give the justification of the construction

Q.

3, 6 and 5 are in continued proportion

1. True

2. False

Q. If $a,b,c$ are in continued proportion prove that:
(i) $\frac{a^2+ab+b^2}{b^2+bc+c^2}=\frac{a}{c}$
(ii) $\frac{a^2+b^2+c^2}{{(a+b+c)}^2}=\frac{a-b+c}{a+b+c}$

Q.

Determine if the following is in proportion.

$5,9,15,27$

Q.

Check whether the following is in continued proportion or not.$12,20\mathrm{and}25.$

Q. Find the mean proportional between: $3$ and $27$

Q.

the First , second and Fourth terms of a proportion are $40,30$and $45$respectively.Find the third term.

Q. Find the mean proportion to $8,16$

Q. Find the mean proportion between $4$ and $25$.

Q. Find the mean proportional between: $16$ and $4$

Q. Find the mean proportional between $\frac{1}{4}$ and $\frac{1}{25}$.

Q. The scale of a map is $1:500000$ what is the actual distance between the places, if they are $2.5cm$ apart on the map?

Q.

Tatesville has x inches of rainfall in April, $(x+1.3)inches$ of rainfall in May, and $(2x+0.5)inches$ in June. Which expression shows the total amount of rainfall for Tatesville for the three-month period? If the rainfall in May was 2.5 inches, find the total rainfall over the three months. [4 MARKS]

Q. Find the mean proportion to $0.3,2.7$

Q. Mean proportional between 7 and 28 is

1. 14
2. 16
3. 17
4. 12

Q. If $b$ is the mean proportion between $a$ and $c$, show that.
$\frac{a^4+a^2{b}^2+b^4}{b^4+b^2{c}^2+c^4}=\frac{a^2}{c^2}$

Q.

Find the value of a:
$43=a\times 4+1\times 3$

___

Q. In England the population increased $15.9$ per cent, between $1871$ and $1881$; if the town population increased $18$ per cent, and the country population $4$ per cent, compare the town and country populations is $1871$.

Q. a, b, c are in continued proportion and if $a=6$ and $c=24$ then find 'b'.