Home / 478.31-661.17-399.16

Finding the Fourth Proportional to 478.31, 661.17 and 399.16

Calculator

Solution

The fourth proportional to 478.31, 661.17 and 399.16 is: 551.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.31 : 661.17 = 399.16 : x
  2. Step 2: Convert to fraction form
    478.31/661.17 = 399.16/x
  3. Step 3: Cross multiply
    478.31x = 661.17 × 399.16
  4. Step 4: Simplify right side
    478.31x = 263,911.62
  5. Step 5: Solve for x
    x = 263,911.62/478.31
  6. Step 6: Final answer
    x = 551.76

Related Problems

Find fourth proportional to 239.15, 330.58 and 199.58
Half scale
Find fourth proportional to 956.61, 1,322.34 and 798.32
Double scale
Find fourth proportional to 479.31, 662.55 and 400.16
Similar ratio
Find fourth proportional to 717.46, 991.75 and 598.74
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.