Home / 1,390.24-2,085.42-688.12

Finding the Fourth Proportional to 1,390.24, 2,085.42 and 688.12

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Solution

The fourth proportional to 1,390.24, 2,085.42 and 688.12 is: 1,032.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,390.24 : 2,085.42 = 688.12 : x
  2. Step 2: Convert to fraction form
    1,390.24/2,085.42 = 688.12/x
  3. Step 3: Cross multiply
    1,390.24x = 2,085.42 × 688.12
  4. Step 4: Simplify right side
    1,390.24x = 1,435,019.21
  5. Step 5: Solve for x
    x = 1,435,019.21/1,390.24
  6. Step 6: Final answer
    x = 1,032.21

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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.