Home / 478.21-660.09-310.39

Finding the Fourth Proportional to 478.21, 660.09 and 310.39

Calculator

Solution

The fourth proportional to 478.21, 660.09 and 310.39 is: 428.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.21 : 660.09 = 310.39 : x
  2. Step 2: Convert to fraction form
    478.21/660.09 = 310.39/x
  3. Step 3: Cross multiply
    478.21x = 660.09 × 310.39
  4. Step 4: Simplify right side
    478.21x = 204,885.34
  5. Step 5: Solve for x
    x = 204,885.34/478.21
  6. Step 6: Final answer
    x = 428.44

Related Problems

Find fourth proportional to 239.11, 330.05 and 155.20
Half scale
Find fourth proportional to 956.42, 1,320.18 and 620.78
Double scale
Find fourth proportional to 479.21, 661.47 and 311.39
Similar ratio
Find fourth proportional to 717.32, 990.14 and 465.59
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.