Home / 759.20-1,139.48-320.78

Finding the Fourth Proportional to 759.20, 1,139.48 and 320.78

Calculator

Solution

The fourth proportional to 759.20, 1,139.48 and 320.78 is: 481.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    759.20 : 1,139.48 = 320.78 : x
  2. Step 2: Convert to fraction form
    759.20/1,139.48 = 320.78/x
  3. Step 3: Cross multiply
    759.20x = 1,139.48 × 320.78
  4. Step 4: Simplify right side
    759.20x = 365,517.50
  5. Step 5: Solve for x
    x = 365,517.50/759.20
  6. Step 6: Final answer
    x = 481.45

Related Problems

Find fourth proportional to 379.60, 569.74 and 160.39
Half scale
Find fourth proportional to 1,518.39, 2,278.97 and 641.55
Double scale
Find fourth proportional to 760.20, 1,140.98 and 321.78
Similar ratio
Find fourth proportional to 1,138.79, 1,709.22 and 481.16
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.