Home / 243.20-364.85-81

Finding the Fourth Proportional to 243.20, 364.85 and 81

Calculator

Solution

The fourth proportional to 243.20, 364.85 and 81 is: 121.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    243.20 : 364.85 = 81 : x
  2. Step 2: Convert to fraction form
    243.20/364.85 = 81/x
  3. Step 3: Cross multiply
    243.20x = 364.85 × 81
  4. Step 4: Simplify right side
    243.20x = 29,552.45
  5. Step 5: Solve for x
    x = 29,552.45/243.20
  6. Step 6: Final answer
    x = 121.52

Related Problems

Find fourth proportional to 121.60, 182.42 and 40.50
Half scale
Find fourth proportional to 486.39, 729.69 and 162
Double scale
Find fourth proportional to 244.20, 366.35 and 82
Similar ratio
Find fourth proportional to 364.79, 547.27 and 121.50
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.