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Finding the Fourth Proportional to 897.84, 1,239.62 and 687.64

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Solution

The fourth proportional to 897.84, 1,239.62 and 687.64 is: 949.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    897.84 : 1,239.62 = 687.64 : x
  2. Step 2: Convert to fraction form
    897.84/1,239.62 = 687.64/x
  3. Step 3: Cross multiply
    897.84x = 1,239.62 × 687.64
  4. Step 4: Simplify right side
    897.84x = 852,412.30
  5. Step 5: Solve for x
    x = 852,412.30/897.84
  6. Step 6: Final answer
    x = 949.40

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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.