Home / 822.80-1,235.64-438.80

Finding the Fourth Proportional to 822.80, 1,235.64 and 438.80

Calculator

Solution

The fourth proportional to 822.80, 1,235.64 and 438.80 is: 658.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    822.80 : 1,235.64 = 438.80 : x
  2. Step 2: Convert to fraction form
    822.80/1,235.64 = 438.80/x
  3. Step 3: Cross multiply
    822.80x = 1,235.64 × 438.80
  4. Step 4: Simplify right side
    822.80x = 542,198.83
  5. Step 5: Solve for x
    x = 542,198.83/822.80
  6. Step 6: Final answer
    x = 658.97

Related Problems

Find fourth proportional to 411.40, 617.82 and 219.40
Half scale
Find fourth proportional to 1,645.60, 2,471.28 and 877.60
Double scale
Find fourth proportional to 823.80, 1,237.14 and 439.80
Similar ratio
Find fourth proportional to 1,234.20, 1,853.46 and 658.20
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.