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Finding the Fourth Proportional to 643.65, 965.48 and 507.42

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Solution

The fourth proportional to 643.65, 965.48 and 507.42 is: 761.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.65 : 965.48 = 507.42 : x
  2. Step 2: Convert to fraction form
    643.65/965.48 = 507.42/x
  3. Step 3: Cross multiply
    643.65x = 965.48 × 507.42
  4. Step 4: Simplify right side
    643.65x = 489,903.86
  5. Step 5: Solve for x
    x = 489,903.86/643.65
  6. Step 6: Final answer
    x = 761.13

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Double scale
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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.