Home / 108.42-149.62-61.80

Finding the Fourth Proportional to 108.42, 149.62 and 61.80

Calculator

Solution

The fourth proportional to 108.42, 149.62 and 61.80 is: 85.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.42 : 149.62 = 61.80 : x
  2. Step 2: Convert to fraction form
    108.42/149.62 = 61.80/x
  3. Step 3: Cross multiply
    108.42x = 149.62 × 61.80
  4. Step 4: Simplify right side
    108.42x = 9,246.47
  5. Step 5: Solve for x
    x = 9,246.47/108.42
  6. Step 6: Final answer
    x = 85.28

Related Problems

Find fourth proportional to 54.21, 74.81 and 30.90
Half scale
Find fourth proportional to 216.84, 299.25 and 123.60
Double scale
Find fourth proportional to 109.42, 151 and 62.80
Similar ratio
Find fourth proportional to 162.63, 224.44 and 92.70
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.