Home / 72.64-109.75-72

Finding the Fourth Proportional to 72.64, 109.75 and 72

Calculator

Solution

The fourth proportional to 72.64, 109.75 and 72 is: 108.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.64 : 109.75 = 72 : x
  2. Step 2: Convert to fraction form
    72.64/109.75 = 72/x
  3. Step 3: Cross multiply
    72.64x = 109.75 × 72
  4. Step 4: Simplify right side
    72.64x = 7,902
  5. Step 5: Solve for x
    x = 7,902/72.64
  6. Step 6: Final answer
    x = 108.78

Related Problems

Find fourth proportional to 36.32, 54.88 and 36
Half scale
Find fourth proportional to 145.28, 219.50 and 144
Double scale
Find fourth proportional to 73.64, 111.26 and 73
Similar ratio
Find fourth proportional to 108.96, 164.63 and 108
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.