Home / 627.39-865.49-391.28

Finding the Fourth Proportional to 627.39, 865.49 and 391.28

Calculator

Solution

The fourth proportional to 627.39, 865.49 and 391.28 is: 539.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    627.39 : 865.49 = 391.28 : x
  2. Step 2: Convert to fraction form
    627.39/865.49 = 391.28/x
  3. Step 3: Cross multiply
    627.39x = 865.49 × 391.28
  4. Step 4: Simplify right side
    627.39x = 338,642.64
  5. Step 5: Solve for x
    x = 338,642.64/627.39
  6. Step 6: Final answer
    x = 539.76

Related Problems

Find fourth proportional to 313.70, 432.74 and 195.64
Half scale
Find fourth proportional to 1,254.78, 1,730.97 and 782.55
Double scale
Find fourth proportional to 628.39, 866.86 and 392.28
Similar ratio
Find fourth proportional to 941.09, 1,298.23 and 586.91
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.