Home / 122.40-183.48-81.72

Finding the Fourth Proportional to 122.40, 183.48 and 81.72

Calculator

Solution

The fourth proportional to 122.40, 183.48 and 81.72 is: 122.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.40 : 183.48 = 81.72 : x
  2. Step 2: Convert to fraction form
    122.40/183.48 = 81.72/x
  3. Step 3: Cross multiply
    122.40x = 183.48 × 81.72
  4. Step 4: Simplify right side
    122.40x = 14,993.99
  5. Step 5: Solve for x
    x = 14,993.99/122.40
  6. Step 6: Final answer
    x = 122.50

Related Problems

Find fourth proportional to 61.20, 91.74 and 40.86
Half scale
Find fourth proportional to 244.80, 366.96 and 163.44
Double scale
Find fourth proportional to 123.40, 184.98 and 82.72
Similar ratio
Find fourth proportional to 183.60, 275.22 and 122.58
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.