Home / 144-215.81-78.90

Finding the Fourth Proportional to 144, 215.81 and 78.90

Calculator

Solution

The fourth proportional to 144, 215.81 and 78.90 is: 118.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    144 : 215.81 = 78.90 : x
  2. Step 2: Convert to fraction form
    144/215.81 = 78.90/x
  3. Step 3: Cross multiply
    144x = 215.81 × 78.90
  4. Step 4: Simplify right side
    144x = 17,027.55
  5. Step 5: Solve for x
    x = 17,027.55/144
  6. Step 6: Final answer
    x = 118.25

Related Problems

Find fourth proportional to 72, 107.90 and 39.45
Half scale
Find fourth proportional to 288, 431.61 and 157.81
Double scale
Find fourth proportional to 145, 217.30 and 79.90
Similar ratio
Find fourth proportional to 216, 323.71 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.