Home / 410.60-615.40-280.60

Finding the Fourth Proportional to 410.60, 615.40 and 280.60

Calculator

Solution

The fourth proportional to 410.60, 615.40 and 280.60 is: 420.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    410.60 : 615.40 = 280.60 : x
  2. Step 2: Convert to fraction form
    410.60/615.40 = 280.60/x
  3. Step 3: Cross multiply
    410.60x = 615.40 × 280.60
  4. Step 4: Simplify right side
    410.60x = 172,681.24
  5. Step 5: Solve for x
    x = 172,681.24/410.60
  6. Step 6: Final answer
    x = 420.56

Related Problems

Find fourth proportional to 205.30, 307.70 and 140.30
Half scale
Find fourth proportional to 821.20, 1,230.80 and 561.20
Double scale
Find fourth proportional to 411.60, 616.90 and 281.60
Similar ratio
Find fourth proportional to 615.90, 923.10 and 420.90
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.