Home / 456.39-684.38-408.20

Finding the Fourth Proportional to 456.39, 684.38 and 408.20

Calculator

Solution

The fourth proportional to 456.39, 684.38 and 408.20 is: 612.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    456.39 : 684.38 = 408.20 : x
  2. Step 2: Convert to fraction form
    456.39/684.38 = 408.20/x
  3. Step 3: Cross multiply
    456.39x = 684.38 × 408.20
  4. Step 4: Simplify right side
    456.39x = 279,361.51
  5. Step 5: Solve for x
    x = 279,361.51/456.39
  6. Step 6: Final answer
    x = 612.11

Related Problems

Find fourth proportional to 228.20, 342.19 and 204.10
Half scale
Find fourth proportional to 912.78, 1,368.77 and 816.39
Double scale
Find fourth proportional to 457.39, 685.88 and 409.20
Similar ratio
Find fourth proportional to 684.59, 1,026.57 and 612.29
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.