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Finding the Fourth Proportional to 661.42, 991.78 and 353.19

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Solution

The fourth proportional to 661.42, 991.78 and 353.19 is: 529.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.42 : 991.78 = 353.19 : x
  2. Step 2: Convert to fraction form
    661.42/991.78 = 353.19/x
  3. Step 3: Cross multiply
    661.42x = 991.78 × 353.19
  4. Step 4: Simplify right side
    661.42x = 350,286.78
  5. Step 5: Solve for x
    x = 350,286.78/661.42
  6. Step 6: Final answer
    x = 529.60

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1.5x scale

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.