Home / 86,520-129,780-20,856

Finding the Fourth Proportional to 86,520, 129,780 and 20,856

Calculator

Solution

The fourth proportional to 86,520, 129,780 and 20,856 is: 31,284

Step by Step Solution

  1. Step 1: Write the proportion equation
    86,520 : 129,780 = 20,856 : x
  2. Step 2: Convert to fraction form
    86,520/129,780 = 20,856/x
  3. Step 3: Cross multiply
    86,520x = 129,780 × 20,856
  4. Step 4: Simplify right side
    86,520x = 2,706,691,680
  5. Step 5: Solve for x
    x = 2,706,691,680/86,520
  6. Step 6: Final answer
    x = 31,284

Related Problems

Find fourth proportional to 43,260, 64,890 and 10,428
Half scale
Find fourth proportional to 173,040, 259,560 and 41,712
Double scale
Find fourth proportional to 86,521, 129,781.50 and 20,857
Similar ratio
Find fourth proportional to 129,780, 194,670 and 31,284
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.