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Finding the Fourth Proportional to 858.72, 1,185 and 509.28

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Solution

The fourth proportional to 858.72, 1,185 and 509.28 is: 702.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.72 : 1,185 = 509.28 : x
  2. Step 2: Convert to fraction form
    858.72/1,185 = 509.28/x
  3. Step 3: Cross multiply
    858.72x = 1,185 × 509.28
  4. Step 4: Simplify right side
    858.72x = 603,496.80
  5. Step 5: Solve for x
    x = 603,496.80/858.72
  6. Step 6: Final answer
    x = 702.79

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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.