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Finding the Fourth Proportional to 305.40, 420.48 and 261.48

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Solution

The fourth proportional to 305.40, 420.48 and 261.48 is: 360.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.40 : 420.48 = 261.48 : x
  2. Step 2: Convert to fraction form
    305.40/420.48 = 261.48/x
  3. Step 3: Cross multiply
    305.40x = 420.48 × 261.48
  4. Step 4: Simplify right side
    305.40x = 109,947.11
  5. Step 5: Solve for x
    x = 109,947.11/305.40
  6. Step 6: Final answer
    x = 360.01

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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.