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Finding the Fourth Proportional to 307.55, 421.68 and 291.89

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Solution

The fourth proportional to 307.55, 421.68 and 291.89 is: 400.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    307.55 : 421.68 = 291.89 : x
  2. Step 2: Convert to fraction form
    307.55/421.68 = 291.89/x
  3. Step 3: Cross multiply
    307.55x = 421.68 × 291.89
  4. Step 4: Simplify right side
    307.55x = 123,082.07
  5. Step 5: Solve for x
    x = 123,082.07/307.55
  6. Step 6: Final answer
    x = 400.21

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.