Home / 438.80-615.40-438.80

Finding the Fourth Proportional to 438.80, 615.40 and 438.80

Calculator

Solution

The fourth proportional to 438.80, 615.40 and 438.80 is: 615.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.80 : 615.40 = 438.80 : x
  2. Step 2: Convert to fraction form
    438.80/615.40 = 438.80/x
  3. Step 3: Cross multiply
    438.80x = 615.40 × 438.80
  4. Step 4: Simplify right side
    438.80x = 270,037.52
  5. Step 5: Solve for x
    x = 270,037.52/438.80
  6. Step 6: Final answer
    x = 615.40

Related Problems

Find fourth proportional to 219.40, 307.70 and 219.40
Half scale
Find fourth proportional to 877.60, 1,230.80 and 877.60
Double scale
Find fourth proportional to 439.80, 616.80 and 439.80
Similar ratio
Find fourth proportional to 658.20, 923.10 and 658.20
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.