Home / 458.09-687.13-430.78

Finding the Fourth Proportional to 458.09, 687.13 and 430.78

Calculator

Solution

The fourth proportional to 458.09, 687.13 and 430.78 is: 646.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.09 : 687.13 = 430.78 : x
  2. Step 2: Convert to fraction form
    458.09/687.13 = 430.78/x
  3. Step 3: Cross multiply
    458.09x = 687.13 × 430.78
  4. Step 4: Simplify right side
    458.09x = 296,001.86
  5. Step 5: Solve for x
    x = 296,001.86/458.09
  6. Step 6: Final answer
    x = 646.17

Related Problems

Find fourth proportional to 229.05, 343.57 and 215.39
Half scale
Find fourth proportional to 916.18, 1,374.26 and 861.56
Double scale
Find fourth proportional to 459.09, 688.63 and 431.78
Similar ratio
Find fourth proportional to 687.14, 1,030.70 and 646.17
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.