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Finding the Fourth Proportional to 628.05, 866.90 and 407

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Solution

The fourth proportional to 628.05, 866.90 and 407 is: 561.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.05 : 866.90 = 407 : x
  2. Step 2: Convert to fraction form
    628.05/866.90 = 407/x
  3. Step 3: Cross multiply
    628.05x = 866.90 × 407
  4. Step 4: Simplify right side
    628.05x = 352,828.30
  5. Step 5: Solve for x
    x = 352,828.30/628.05
  6. Step 6: Final answer
    x = 561.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.