Solve the Proportion 4/7 = x/28 (Answer: x = 16)

Exact Answer

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Problem: Solve the Proportion 4/7 = x/28
Formula / Expression: 4/7 = x/28 → x = 16
Final Answer: x = 16
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Step-by-Step Solution:

Step 1: Set Up the Proportion Equation
Write the proportion equating the two ratios:
4 / 7 = x / 28
Working: 4/7 = x/28

Step 2: Apply the Cross-Multiplication Property
In any true proportion A/B = C/D, the cross products are always equal: A × D = B × C.
Multiplying diagonally: (4) × (28) = (7) × (x).
Working: (4) × (28) = (7) × (x)

Step 3: Isolate the Unknown Variable x
Combine known numbers to obtain a simple one-step linear equation:
7 × x = 112.
Working: 7x = 112

Step 4: Divide to Solve for x
Divide both sides of the equation by 7:
x = 112 ÷ 7 = 16.
Working: x = 112 / 7 = 16

Step 5: Verify Proportion and Scale Multiplier
Check your work: Substituting x = 16 gives both fractions a ratio of 4x. Both fractions evaluate to the exact same value, confirming the solution is 100% correct.
Working: Check: (4 ÷ 7) = (16 ÷ 28)

Key Values:
- Solved Value (x): x = 16
- Equation: 4/7 = x/28
- Cross Product: 112
- Scale Multiplier: 4x

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Solved with FractionsCalc:
https://fractionscalc.com/solve-proportion-4-7-equals-x-28/
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47 = x28 → x = 16

Solved Value (x)

x = 16

Equation

4/7 = x/28

Cross Product

112

Scale Multiplier

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Step-by-Step Solution: 4/7 = x/28 → x = 16

Step 1

Set Up the Proportion Equation

Write the proportion equating the two ratios:
4 / 7 = x / 28

4/7 = x/28

Step 2

Apply the Cross-Multiplication Property

In any true proportion A/B = C/D, the cross products are always equal: A × D = B × C.
Multiplying diagonally: (4) × (28) = (7) × (x).

(4) × (28) = (7) × (x)

Step 3

Isolate the Unknown Variable x

Combine known numbers to obtain a simple one-step linear equation:
7 × x = 112.

7x = 112

Step 4

Divide to Solve for x

Divide both sides of the equation by 7:
x = 112 ÷ 7 = 16.

x = 112 / 7 = 16

Step 5

Verify Proportion and Scale Multiplier

Check your work: Substituting x = 16 gives both fractions a ratio of 4x. Both fractions evaluate to the exact same value, confirming the solution is 100% correct.

Check: (4 ÷ 7) = (16 ÷ 28)

Visual Representation

The diagram below illustrates Solve proportion 4/7 = x/28 visually:

Summary & Alternative Representations

Property / Format	Value
Solved Value (x)	`x = 16`
Equation	`4/7 = x/28`
Cross Product	`112`
Scale Multiplier	`4x`

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Frequently Asked Questions

How do you solve for x in the proportion 4/7 = x/28?

Cross-multiply diagonally: multiply the known diagonal pair (4 × 28 = 112) and then divide by the coefficient paired with x (7), resulting in x = 16.

What is the cross multiplication rule for proportions?

For any proportion A/B = C/D, the product of the extremes (A × D) is always equal to the product of the means (B × C).

Can a proportion have decimal answers?

Yes! If the cross-product is not evenly divisible by the coefficient, the result can be written as an exact decimal or as a simplified fraction / mixed number.