Home / 428-642-124

Finding the Fourth Proportional to 428, 642 and 124

Calculator

Solution

The fourth proportional to 428, 642 and 124 is: 186

Step by Step Solution

  1. Step 1: Write the proportion equation
    428 : 642 = 124 : x
  2. Step 2: Convert to fraction form
    428/642 = 124/x
  3. Step 3: Cross multiply
    428x = 642 × 124
  4. Step 4: Simplify right side
    428x = 79,608
  5. Step 5: Solve for x
    x = 79,608/428
  6. Step 6: Final answer
    x = 186

Related Problems

Find fourth proportional to 214, 321 and 62
Half scale
Find fourth proportional to 856, 1,284 and 248
Double scale
Find fourth proportional to 429, 643.50 and 125
Similar ratio
Find fourth proportional to 642, 963 and 186
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.