Home / 1,389.32-2,084.09-415.40

Finding the Fourth Proportional to 1,389.32, 2,084.09 and 415.40

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Solution

The fourth proportional to 1,389.32, 2,084.09 and 415.40 is: 623.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.32 : 2,084.09 = 415.40 : x
  2. Step 2: Convert to fraction form
    1,389.32/2,084.09 = 415.40/x
  3. Step 3: Cross multiply
    1,389.32x = 2,084.09 × 415.40
  4. Step 4: Simplify right side
    1,389.32x = 865,734.12
  5. Step 5: Solve for x
    x = 865,734.12/1,389.32
  6. Step 6: Final answer
    x = 623.14

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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.