Home / 106.20-159-90

Finding the Fourth Proportional to 106.20, 159 and 90

Calculator

Solution

The fourth proportional to 106.20, 159 and 90 is: 134.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    106.20 : 159 = 90 : x
  2. Step 2: Convert to fraction form
    106.20/159 = 90/x
  3. Step 3: Cross multiply
    106.20x = 159 × 90
  4. Step 4: Simplify right side
    106.20x = 14,310
  5. Step 5: Solve for x
    x = 14,310/106.20
  6. Step 6: Final answer
    x = 134.75

Related Problems

Find fourth proportional to 53.10, 79.50 and 45
Half scale
Find fourth proportional to 212.40, 318 and 180
Double scale
Find fourth proportional to 107.20, 160.50 and 91
Similar ratio
Find fourth proportional to 159.30, 238.50 and 135
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.