Home / 497.59-686.68-287.78

Finding the Fourth Proportional to 497.59, 686.68 and 287.78

Calculator

Solution

The fourth proportional to 497.59, 686.68 and 287.78 is: 397.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    497.59 : 686.68 = 287.78 : x
  2. Step 2: Convert to fraction form
    497.59/686.68 = 287.78/x
  3. Step 3: Cross multiply
    497.59x = 686.68 × 287.78
  4. Step 4: Simplify right side
    497.59x = 197,608.62
  5. Step 5: Solve for x
    x = 197,608.62/497.59
  6. Step 6: Final answer
    x = 397.13

Related Problems

Find fourth proportional to 248.79, 343.34 and 143.89
Half scale
Find fourth proportional to 995.18, 1,373.36 and 575.55
Double scale
Find fourth proportional to 498.59, 688.06 and 288.78
Similar ratio
Find fourth proportional to 746.38, 1,030.02 and 431.66
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.