Home / 143.31-197.78-81.15

Finding the Fourth Proportional to 143.31, 197.78 and 81.15

Calculator

Solution

The fourth proportional to 143.31, 197.78 and 81.15 is: 111.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.31 : 197.78 = 81.15 : x
  2. Step 2: Convert to fraction form
    143.31/197.78 = 81.15/x
  3. Step 3: Cross multiply
    143.31x = 197.78 × 81.15
  4. Step 4: Simplify right side
    143.31x = 16,049.15
  5. Step 5: Solve for x
    x = 16,049.15/143.31
  6. Step 6: Final answer
    x = 111.99

Related Problems

Find fourth proportional to 71.65, 98.89 and 40.57
Half scale
Find fourth proportional to 286.62, 395.56 and 162.30
Double scale
Find fourth proportional to 144.31, 199.16 and 82.15
Similar ratio
Find fourth proportional to 214.96, 296.67 and 121.72
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.