Home / 198.90-298.47-102.78

Finding the Fourth Proportional to 198.90, 298.47 and 102.78

Calculator

Solution

The fourth proportional to 198.90, 298.47 and 102.78 is: 154.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.90 : 298.47 = 102.78 : x
  2. Step 2: Convert to fraction form
    198.90/298.47 = 102.78/x
  3. Step 3: Cross multiply
    198.90x = 298.47 × 102.78
  4. Step 4: Simplify right side
    198.90x = 30,676.75
  5. Step 5: Solve for x
    x = 30,676.75/198.90
  6. Step 6: Final answer
    x = 154.23

Related Problems

Find fourth proportional to 99.45, 149.24 and 51.39
Half scale
Find fourth proportional to 397.80, 596.94 and 205.56
Double scale
Find fourth proportional to 199.90, 299.97 and 103.78
Similar ratio
Find fourth proportional to 298.35, 447.71 and 154.17
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.