Find [tex]$x$[/tex] in the following proportions:

(a) [tex]$x, 6, 55, 11$[/tex]

(b) [tex][tex]$16, 18, x, 108$[/tex][/tex]

(c) [tex]$4, x, x, 16$[/tex]



Answer :

Sure, let's solve these proportions step-by-step.

### Part (a):
We are given the proportion: [tex]\(\frac{x}{6} = \frac{55}{11}\)[/tex].

1. First, we'll set up the equation:
[tex]\[\frac{x}{6} = \frac{55}{11}\][/tex]

2. Cross-multiply to solve for [tex]\(x\)[/tex]:
[tex]\[x \cdot 11 = 6 \cdot 55\][/tex]

3. Calculate the right-hand side of the equation:
[tex]\[6 \cdot 55 = 330\][/tex]

4. Now solve for [tex]\(x\)[/tex]:
[tex]\[x \cdot 11 = 330 \implies x = \frac{330}{11}\][/tex]

5. Simplify the fraction:
[tex]\[x = 30\][/tex]

So, the value of [tex]\(x\)[/tex] in part (a) is [tex]\(30.0\)[/tex].

### Part (b):
We are given the proportion: [tex]\(\frac{16}{18} = \frac{x}{108}\)[/tex].

1. First, we'll set up the equation:
[tex]\[\frac{16}{18} = \frac{x}{108}\][/tex]

2. Cross-multiply to solve for [tex]\(x\)[/tex]:
[tex]\[16 \cdot 108 = 18 \cdot x\][/tex]

3. Calculate the left-hand side of the equation:
[tex]\[16 \cdot 108 = 1728\][/tex]

4. Now solve for [tex]\(x\)[/tex]:
[tex]\[1728 = 18 \cdot x \implies x = \frac{1728}{18}\][/tex]

5. Simplify the fraction:
[tex]\[x = 96\][/tex]

So, the value of [tex]\(x\)[/tex] in part (b) is [tex]\(96.0\)[/tex].

### Part (c):
We are given the proportion: [tex]\(\frac{4}{x} = \frac{x}{16}\)[/tex].

1. First, we'll set up the equation:
[tex]\[\frac{4}{x} = \frac{x}{16}\][/tex]

2. Cross-multiply to solve for [tex]\(x\)[/tex]:
[tex]\[4 \cdot 16 = x \cdot x\][/tex]

3. Simplify the left-hand side of the equation:
[tex]\[64 = x^2\][/tex]

4. Solve for [tex]\(x\)[/tex] by taking the square root of both sides:
[tex]\[x = \sqrt{64}\][/tex]

5. Calculate the square root:
[tex]\[x = 8\][/tex]

So, the value of [tex]\(x\)[/tex] in part (c) is [tex]\(8.0\)[/tex].

In summary, the solutions for the given proportions are:
- [tex]\(x = 30.0\)[/tex] in part (a)
- [tex]\(x = 96.0\)[/tex] in part (b)
- [tex]\(x = 8.0\)[/tex] in part (c)