Home / 73-100.80-64.90

Finding the Fourth Proportional to 73, 100.80 and 64.90

Calculator

Solution

The fourth proportional to 73, 100.80 and 64.90 is: 89.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    73 : 100.80 = 64.90 : x
  2. Step 2: Convert to fraction form
    73/100.80 = 64.90/x
  3. Step 3: Cross multiply
    73x = 100.80 × 64.90
  4. Step 4: Simplify right side
    73x = 6,541.92
  5. Step 5: Solve for x
    x = 6,541.92/73
  6. Step 6: Final answer
    x = 89.62

Related Problems

Find fourth proportional to 36.50, 50.40 and 32.45
Half scale
Find fourth proportional to 146, 201.60 and 129.80
Double scale
Find fourth proportional to 74, 102.18 and 65.90
Similar ratio
Find fourth proportional to 109.50, 151.20 and 97.35
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.