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Finding the Fourth Proportional to 840.36, 1,159.80 and 491.16

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Solution

The fourth proportional to 840.36, 1,159.80 and 491.16 is: 677.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.36 : 1,159.80 = 491.16 : x
  2. Step 2: Convert to fraction form
    840.36/1,159.80 = 491.16/x
  3. Step 3: Cross multiply
    840.36x = 1,159.80 × 491.16
  4. Step 4: Simplify right side
    840.36x = 569,647.37
  5. Step 5: Solve for x
    x = 569,647.37/840.36
  6. Step 6: Final answer
    x = 677.86

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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.