Home / 855-1,179.90-487

Finding the Fourth Proportional to 855, 1,179.90 and 487

Calculator

Solution

The fourth proportional to 855, 1,179.90 and 487 is: 672.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    855 : 1,179.90 = 487 : x
  2. Step 2: Convert to fraction form
    855/1,179.90 = 487/x
  3. Step 3: Cross multiply
    855x = 1,179.90 × 487
  4. Step 4: Simplify right side
    855x = 574,611.30
  5. Step 5: Solve for x
    x = 574,611.30/855
  6. Step 6: Final answer
    x = 672.06

Related Problems

Find fourth proportional to 427.50, 589.95 and 243.50
Half scale
Find fourth proportional to 1,710, 2,359.80 and 974
Double scale
Find fourth proportional to 856, 1,181.28 and 488
Similar ratio
Find fourth proportional to 1,282.50, 1,769.85 and 730.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.