Home / 106.61-159.86-90.31

Finding the Fourth Proportional to 106.61, 159.86 and 90.31

Calculator

Solution

The fourth proportional to 106.61, 159.86 and 90.31 is: 135.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    106.61 : 159.86 = 90.31 : x
  2. Step 2: Convert to fraction form
    106.61/159.86 = 90.31/x
  3. Step 3: Cross multiply
    106.61x = 159.86 × 90.31
  4. Step 4: Simplify right side
    106.61x = 14,435.71
  5. Step 5: Solve for x
    x = 14,435.71/106.61
  6. Step 6: Final answer
    x = 135.41

Related Problems

Find fourth proportional to 53.30, 79.93 and 45.15
Half scale
Find fourth proportional to 213.21, 319.71 and 180.61
Double scale
Find fourth proportional to 107.61, 161.35 and 91.31
Similar ratio
Find fourth proportional to 159.91, 239.78 and 135.46
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.