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Finding the Fourth Proportional to 420.66, 631.60 and 407.34

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Solution

The fourth proportional to 420.66, 631.60 and 407.34 is: 611.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.66 : 631.60 = 407.34 : x
  2. Step 2: Convert to fraction form
    420.66/631.60 = 407.34/x
  3. Step 3: Cross multiply
    420.66x = 631.60 × 407.34
  4. Step 4: Simplify right side
    420.66x = 257,275.94
  5. Step 5: Solve for x
    x = 257,275.94/420.66
  6. Step 6: Final answer
    x = 611.60

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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.