Home / 124.72-172-87.42

Finding the Fourth Proportional to 124.72, 172 and 87.42

Calculator

Solution

The fourth proportional to 124.72, 172 and 87.42 is: 120.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.72 : 172 = 87.42 : x
  2. Step 2: Convert to fraction form
    124.72/172 = 87.42/x
  3. Step 3: Cross multiply
    124.72x = 172 × 87.42
  4. Step 4: Simplify right side
    124.72x = 15,036.24
  5. Step 5: Solve for x
    x = 15,036.24/124.72
  6. Step 6: Final answer
    x = 120.56

Related Problems

Find fourth proportional to 62.36, 86 and 43.71
Half scale
Find fourth proportional to 249.44, 344 and 174.84
Double scale
Find fourth proportional to 125.72, 173.38 and 88.42
Similar ratio
Find fourth proportional to 187.08, 258 and 131.13
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.