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Finding the Fourth Proportional to 1,402.50, 2,103.99 and 428.70

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Solution

The fourth proportional to 1,402.50, 2,103.99 and 428.70 is: 643.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,402.50 : 2,103.99 = 428.70 : x
  2. Step 2: Convert to fraction form
    1,402.50/2,103.99 = 428.70/x
  3. Step 3: Cross multiply
    1,402.50x = 2,103.99 × 428.70
  4. Step 4: Simplify right side
    1,402.50x = 901,980.51
  5. Step 5: Solve for x
    x = 901,980.51/1,402.50
  6. Step 6: Final answer
    x = 643.12

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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.