Home / 459.78-686.78-386.88

Finding the Fourth Proportional to 459.78, 686.78 and 386.88

Calculator

Solution

The fourth proportional to 459.78, 686.78 and 386.88 is: 577.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    459.78 : 686.78 = 386.88 : x
  2. Step 2: Convert to fraction form
    459.78/686.78 = 386.88/x
  3. Step 3: Cross multiply
    459.78x = 686.78 × 386.88
  4. Step 4: Simplify right side
    459.78x = 265,699.51
  5. Step 5: Solve for x
    x = 265,699.51/459.78
  6. Step 6: Final answer
    x = 577.88

Related Problems

Find fourth proportional to 229.89, 343.39 and 193.44
Half scale
Find fourth proportional to 919.56, 1,373.55 and 773.76
Double scale
Find fourth proportional to 460.78, 688.27 and 387.88
Similar ratio
Find fourth proportional to 689.67, 1,030.16 and 580.32
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.