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Finding the Fourth Proportional to 690.90, 953.36 and 469.78

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Solution

The fourth proportional to 690.90, 953.36 and 469.78 is: 648.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.90 : 953.36 = 469.78 : x
  2. Step 2: Convert to fraction form
    690.90/953.36 = 469.78/x
  3. Step 3: Cross multiply
    690.90x = 953.36 × 469.78
  4. Step 4: Simplify right side
    690.90x = 447,869.46
  5. Step 5: Solve for x
    x = 447,869.46/690.90
  6. Step 6: Final answer
    x = 648.24

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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.