Home / 355.43-489.84-311.08

Finding the Fourth Proportional to 355.43, 489.84 and 311.08

Calculator

Solution

The fourth proportional to 355.43, 489.84 and 311.08 is: 428.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.43 : 489.84 = 311.08 : x
  2. Step 2: Convert to fraction form
    355.43/489.84 = 311.08/x
  3. Step 3: Cross multiply
    355.43x = 489.84 × 311.08
  4. Step 4: Simplify right side
    355.43x = 152,379.43
  5. Step 5: Solve for x
    x = 152,379.43/355.43
  6. Step 6: Final answer
    x = 428.72

Related Problems

Find fourth proportional to 177.72, 244.92 and 155.54
Half scale
Find fourth proportional to 710.86, 979.68 and 622.16
Double scale
Find fourth proportional to 356.43, 491.22 and 312.08
Similar ratio
Find fourth proportional to 533.15, 734.76 and 466.62
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.