Home / 716.20-988.30-421.43

Finding the Fourth Proportional to 716.20, 988.30 and 421.43

Calculator

Solution

The fourth proportional to 716.20, 988.30 and 421.43 is: 581.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    716.20 : 988.30 = 421.43 : x
  2. Step 2: Convert to fraction form
    716.20/988.30 = 421.43/x
  3. Step 3: Cross multiply
    716.20x = 988.30 × 421.43
  4. Step 4: Simplify right side
    716.20x = 416,494.85
  5. Step 5: Solve for x
    x = 416,494.85/716.20
  6. Step 6: Final answer
    x = 581.54

Related Problems

Find fourth proportional to 358.10, 494.15 and 210.71
Half scale
Find fourth proportional to 1,432.40, 1,976.60 and 842.85
Double scale
Find fourth proportional to 717.20, 989.68 and 422.43
Similar ratio
Find fourth proportional to 1,074.30, 1,482.45 and 632.14
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.