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Finding the Fourth Proportional to 390.89, 585.57 and 313.49

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Solution

The fourth proportional to 390.89, 585.57 and 313.49 is: 469.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.89 : 585.57 = 313.49 : x
  2. Step 2: Convert to fraction form
    390.89/585.57 = 313.49/x
  3. Step 3: Cross multiply
    390.89x = 585.57 × 313.49
  4. Step 4: Simplify right side
    390.89x = 183,570.34
  5. Step 5: Solve for x
    x = 183,570.34/390.89
  6. Step 6: Final answer
    x = 469.62

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.