Home / 469.70-648.20-386.78

Finding the Fourth Proportional to 469.70, 648.20 and 386.78

Calculator

Solution

The fourth proportional to 469.70, 648.20 and 386.78 is: 533.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    469.70 : 648.20 = 386.78 : x
  2. Step 2: Convert to fraction form
    469.70/648.20 = 386.78/x
  3. Step 3: Cross multiply
    469.70x = 648.20 × 386.78
  4. Step 4: Simplify right side
    469.70x = 250,708.52
  5. Step 5: Solve for x
    x = 250,708.52/469.70
  6. Step 6: Final answer
    x = 533.76

Related Problems

Find fourth proportional to 234.85, 324.10 and 193.39
Half scale
Find fourth proportional to 939.40, 1,296.41 and 773.55
Double scale
Find fourth proportional to 470.70, 649.58 and 387.78
Similar ratio
Find fourth proportional to 704.55, 972.30 and 580.16
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.