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Finding the Fourth Proportional to 1,005.66, 1,508.75 and 420.89

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Solution

The fourth proportional to 1,005.66, 1,508.75 and 420.89 is: 631.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,005.66 : 1,508.75 = 420.89 : x
  2. Step 2: Convert to fraction form
    1,005.66/1,508.75 = 420.89/x
  3. Step 3: Cross multiply
    1,005.66x = 1,508.75 × 420.89
  4. Step 4: Simplify right side
    1,005.66x = 635,008.14
  5. Step 5: Solve for x
    x = 635,008.14/1,005.66
  6. Step 6: Final answer
    x = 631.43

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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.