Home / 135-202.50-78

Finding the Fourth Proportional to 135, 202.50 and 78

Calculator

Solution

The fourth proportional to 135, 202.50 and 78 is: 117

Step by Step Solution

  1. Step 1: Write the proportion equation
    135 : 202.50 = 78 : x
  2. Step 2: Convert to fraction form
    135/202.50 = 78/x
  3. Step 3: Cross multiply
    135x = 202.50 × 78
  4. Step 4: Simplify right side
    135x = 15,795
  5. Step 5: Solve for x
    x = 15,795/135
  6. Step 6: Final answer
    x = 117

Related Problems

Find fourth proportional to 67.50, 101.25 and 39
Half scale
Find fourth proportional to 270, 405 and 156
Double scale
Find fourth proportional to 136, 204 and 79
Similar ratio
Find fourth proportional to 202.50, 303.75 and 117
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.