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Finding the Fourth Proportional to 495.78, 684.36 and 309.45

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Solution

The fourth proportional to 495.78, 684.36 and 309.45 is: 427.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    495.78 : 684.36 = 309.45 : x
  2. Step 2: Convert to fraction form
    495.78/684.36 = 309.45/x
  3. Step 3: Cross multiply
    495.78x = 684.36 × 309.45
  4. Step 4: Simplify right side
    495.78x = 211,775.20
  5. Step 5: Solve for x
    x = 211,775.20/495.78
  6. Step 6: Final answer
    x = 427.16

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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.