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Finding the Fourth Proportional to 405.40, 607.58 and 261.16

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Solution

The fourth proportional to 405.40, 607.58 and 261.16 is: 391.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.40 : 607.58 = 261.16 : x
  2. Step 2: Convert to fraction form
    405.40/607.58 = 261.16/x
  3. Step 3: Cross multiply
    405.40x = 607.58 × 261.16
  4. Step 4: Simplify right side
    405.40x = 158,675.59
  5. Step 5: Solve for x
    x = 158,675.59/405.40
  6. Step 6: Final answer
    x = 391.41

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.