Home / 627.80-939.30-411.80

Finding the Fourth Proportional to 627.80, 939.30 and 411.80

Calculator

Solution

The fourth proportional to 627.80, 939.30 and 411.80 is: 616.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    627.80 : 939.30 = 411.80 : x
  2. Step 2: Convert to fraction form
    627.80/939.30 = 411.80/x
  3. Step 3: Cross multiply
    627.80x = 939.30 × 411.80
  4. Step 4: Simplify right side
    627.80x = 386,803.74
  5. Step 5: Solve for x
    x = 386,803.74/627.80
  6. Step 6: Final answer
    x = 616.13

Related Problems

Find fourth proportional to 313.90, 469.65 and 205.90
Half scale
Find fourth proportional to 1,255.60, 1,878.60 and 823.60
Double scale
Find fourth proportional to 628.80, 940.80 and 412.80
Similar ratio
Find fourth proportional to 941.70, 1,408.95 and 617.70
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.