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Finding the Fourth Proportional to 345.21, 475.61 and 312.45

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Solution

The fourth proportional to 345.21, 475.61 and 312.45 is: 430.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    345.21 : 475.61 = 312.45 : x
  2. Step 2: Convert to fraction form
    345.21/475.61 = 312.45/x
  3. Step 3: Cross multiply
    345.21x = 475.61 × 312.45
  4. Step 4: Simplify right side
    345.21x = 148,602.78
  5. Step 5: Solve for x
    x = 148,602.78/345.21
  6. Step 6: Final answer
    x = 430.47

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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.