Home / 410.40-615.60-386.40

Finding the Fourth Proportional to 410.40, 615.60 and 386.40

Calculator

Solution

The fourth proportional to 410.40, 615.60 and 386.40 is: 579.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    410.40 : 615.60 = 386.40 : x
  2. Step 2: Convert to fraction form
    410.40/615.60 = 386.40/x
  3. Step 3: Cross multiply
    410.40x = 615.60 × 386.40
  4. Step 4: Simplify right side
    410.40x = 237,867.84
  5. Step 5: Solve for x
    x = 237,867.84/410.40
  6. Step 6: Final answer
    x = 579.60

Related Problems

Find fourth proportional to 205.20, 307.80 and 193.20
Half scale
Find fourth proportional to 820.80, 1,231.20 and 772.80
Double scale
Find fourth proportional to 411.40, 617.10 and 387.40
Similar ratio
Find fourth proportional to 615.60, 923.40 and 579.60
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.