Home / 372.21-558.35-128.74

Finding the Fourth Proportional to 372.21, 558.35 and 128.74

Calculator

Solution

The fourth proportional to 372.21, 558.35 and 128.74 is: 193.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    372.21 : 558.35 = 128.74 : x
  2. Step 2: Convert to fraction form
    372.21/558.35 = 128.74/x
  3. Step 3: Cross multiply
    372.21x = 558.35 × 128.74
  4. Step 4: Simplify right side
    372.21x = 71,879.94
  5. Step 5: Solve for x
    x = 71,879.94/372.21
  6. Step 6: Final answer
    x = 193.12

Related Problems

Find fourth proportional to 186.11, 279.17 and 64.37
Half scale
Find fourth proportional to 744.42, 1,116.69 and 257.48
Double scale
Find fourth proportional to 373.21, 559.85 and 129.74
Similar ratio
Find fourth proportional to 558.32, 837.52 and 193.11
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.