Home / 478.99-661.31-313.49

Finding the Fourth Proportional to 478.99, 661.31 and 313.49

Calculator

Solution

The fourth proportional to 478.99, 661.31 and 313.49 is: 432.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.99 : 661.31 = 313.49 : x
  2. Step 2: Convert to fraction form
    478.99/661.31 = 313.49/x
  3. Step 3: Cross multiply
    478.99x = 661.31 × 313.49
  4. Step 4: Simplify right side
    478.99x = 207,313.38
  5. Step 5: Solve for x
    x = 207,313.38/478.99
  6. Step 6: Final answer
    x = 432.81

Related Problems

Find fourth proportional to 239.50, 330.66 and 156.74
Half scale
Find fourth proportional to 957.99, 1,322.63 and 626.97
Double scale
Find fourth proportional to 479.99, 662.70 and 314.49
Similar ratio
Find fourth proportional to 718.49, 991.97 and 470.23
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.