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Finding the Fourth Proportional to 678.81, 935.78 and 501.51

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Solution

The fourth proportional to 678.81, 935.78 and 501.51 is: 691.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.81 : 935.78 = 501.51 : x
  2. Step 2: Convert to fraction form
    678.81/935.78 = 501.51/x
  3. Step 3: Cross multiply
    678.81x = 935.78 × 501.51
  4. Step 4: Simplify right side
    678.81x = 469,300.52
  5. Step 5: Solve for x
    x = 469,300.52/678.81
  6. Step 6: Final answer
    x = 691.36

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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.