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Finding the Fourth Proportional to 421.58, 631.66 and 258.91

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Solution

The fourth proportional to 421.58, 631.66 and 258.91 is: 387.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.58 : 631.66 = 258.91 : x
  2. Step 2: Convert to fraction form
    421.58/631.66 = 258.91/x
  3. Step 3: Cross multiply
    421.58x = 631.66 × 258.91
  4. Step 4: Simplify right side
    421.58x = 163,543.09
  5. Step 5: Solve for x
    x = 163,543.09/421.58
  6. Step 6: Final answer
    x = 387.93

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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.