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Finding the Fourth Proportional to 653.48, 978.40 and 409.40

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Solution

The fourth proportional to 653.48, 978.40 and 409.40 is: 612.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.48 : 978.40 = 409.40 : x
  2. Step 2: Convert to fraction form
    653.48/978.40 = 409.40/x
  3. Step 3: Cross multiply
    653.48x = 978.40 × 409.40
  4. Step 4: Simplify right side
    653.48x = 400,556.96
  5. Step 5: Solve for x
    x = 400,556.96/653.48
  6. Step 6: Final answer
    x = 612.96

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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.