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Finding the Fourth Proportional to 458.40, 687.38 and 214.80

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Solution

The fourth proportional to 458.40, 687.38 and 214.80 is: 322.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.40 : 687.38 = 214.80 : x
  2. Step 2: Convert to fraction form
    458.40/687.38 = 214.80/x
  3. Step 3: Cross multiply
    458.40x = 687.38 × 214.80
  4. Step 4: Simplify right side
    458.40x = 147,649.22
  5. Step 5: Solve for x
    x = 147,649.22/458.40
  6. Step 6: Final answer
    x = 322.10

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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.