Home / 93.38-139.85-78.90

Finding the Fourth Proportional to 93.38, 139.85 and 78.90

Calculator

Solution

The fourth proportional to 93.38, 139.85 and 78.90 is: 118.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    93.38 : 139.85 = 78.90 : x
  2. Step 2: Convert to fraction form
    93.38/139.85 = 78.90/x
  3. Step 3: Cross multiply
    93.38x = 139.85 × 78.90
  4. Step 4: Simplify right side
    93.38x = 11,033.77
  5. Step 5: Solve for x
    x = 11,033.77/93.38
  6. Step 6: Final answer
    x = 118.17

Related Problems

Find fourth proportional to 46.69, 69.92 and 39.45
Half scale
Find fourth proportional to 186.75, 279.69 and 157.80
Double scale
Find fourth proportional to 94.38, 141.34 and 79.90
Similar ratio
Find fourth proportional to 140.06, 209.77 and 118.35
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.