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Finding the Fourth Proportional to 287.40, 430.20 and 287.40

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Solution

The fourth proportional to 287.40, 430.20 and 287.40 is: 430.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.40 : 430.20 = 287.40 : x
  2. Step 2: Convert to fraction form
    287.40/430.20 = 287.40/x
  3. Step 3: Cross multiply
    287.40x = 430.20 × 287.40
  4. Step 4: Simplify right side
    287.40x = 123,639.48
  5. Step 5: Solve for x
    x = 123,639.48/287.40
  6. Step 6: Final answer
    x = 430.20

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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.