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Finding the Fourth Proportional to 356.19, 491.43 and 312.30

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Solution

The fourth proportional to 356.19, 491.43 and 312.30 is: 430.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    356.19 : 491.43 = 312.30 : x
  2. Step 2: Convert to fraction form
    356.19/491.43 = 312.30/x
  3. Step 3: Cross multiply
    356.19x = 491.43 × 312.30
  4. Step 4: Simplify right side
    356.19x = 153,473.59
  5. Step 5: Solve for x
    x = 153,473.59/356.19
  6. Step 6: Final answer
    x = 430.88

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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.