Home / 62.88-86.72-40.72

Finding the Fourth Proportional to 62.88, 86.72 and 40.72

Calculator

Solution

The fourth proportional to 62.88, 86.72 and 40.72 is: 56.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    62.88 : 86.72 = 40.72 : x
  2. Step 2: Convert to fraction form
    62.88/86.72 = 40.72/x
  3. Step 3: Cross multiply
    62.88x = 86.72 × 40.72
  4. Step 4: Simplify right side
    62.88x = 3,531.24
  5. Step 5: Solve for x
    x = 3,531.24/62.88
  6. Step 6: Final answer
    x = 56.16

Related Problems

Find fourth proportional to 31.44, 43.36 and 20.36
Half scale
Find fourth proportional to 125.76, 173.44 and 81.44
Double scale
Find fourth proportional to 63.88, 88.10 and 41.72
Similar ratio
Find fourth proportional to 94.32, 130.08 and 61.08
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.