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Finding the Fourth Proportional to 664.71, 916.47 and 428.25

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Solution

The fourth proportional to 664.71, 916.47 and 428.25 is: 590.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.71 : 916.47 = 428.25 : x
  2. Step 2: Convert to fraction form
    664.71/916.47 = 428.25/x
  3. Step 3: Cross multiply
    664.71x = 916.47 × 428.25
  4. Step 4: Simplify right side
    664.71x = 392,478.28
  5. Step 5: Solve for x
    x = 392,478.28/664.71
  6. Step 6: Final answer
    x = 590.45

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.