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Finding the Fourth Proportional to 285.81, 391.51 and 285.00

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Solution

The fourth proportional to 285.81, 391.51 and 285.00 is: 390.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.81 : 391.51 = 285.00 : x
  2. Step 2: Convert to fraction form
    285.81/391.51 = 285.00/x
  3. Step 3: Cross multiply
    285.81x = 391.51 × 285.00
  4. Step 4: Simplify right side
    285.81x = 111,580.04
  5. Step 5: Solve for x
    x = 111,580.04/285.81
  6. Step 6: Final answer
    x = 390.40

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.