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Finding the Fourth Proportional to 1,209, 1,668.42 and 657

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Solution

The fourth proportional to 1,209, 1,668.42 and 657 is: 906.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209 : 1,668.42 = 657 : x
  2. Step 2: Convert to fraction form
    1,209/1,668.42 = 657/x
  3. Step 3: Cross multiply
    1,209x = 1,668.42 × 657
  4. Step 4: Simplify right side
    1,209x = 1,096,151.94
  5. Step 5: Solve for x
    x = 1,096,151.94/1,209
  6. Step 6: Final answer
    x = 906.66

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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.