Home / 512.80-769.20-238.80

Finding the Fourth Proportional to 512.80, 769.20 and 238.80

Calculator

Solution

The fourth proportional to 512.80, 769.20 and 238.80 is: 358.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.80 : 769.20 = 238.80 : x
  2. Step 2: Convert to fraction form
    512.80/769.20 = 238.80/x
  3. Step 3: Cross multiply
    512.80x = 769.20 × 238.80
  4. Step 4: Simplify right side
    512.80x = 183,684.96
  5. Step 5: Solve for x
    x = 183,684.96/512.80
  6. Step 6: Final answer
    x = 358.20

Related Problems

Find fourth proportional to 256.40, 384.60 and 119.40
Half scale
Find fourth proportional to 1,025.60, 1,538.40 and 477.60
Double scale
Find fourth proportional to 513.80, 770.70 and 239.80
Similar ratio
Find fourth proportional to 769.20, 1,153.80 and 358.20
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.