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Finding the Third Proportional to 258 and 398.50

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Solution

The third proportional to 258 and 398.50 is: 615.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    258 : 398.50 = 398.50 : x
  2. Step 2: Convert to fraction form
    258/398.50 = 398.50/x
  3. Step 3: Cross multiply
    258x = 398.50 × 398.50
  4. Step 4: Simplify right side
    258x = 158,802.25
  5. Step 5: Solve for x
    x = 158,802.25/258
  6. Step 6: Final answer
    x = 615.51

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These problems maintain the same ratio (1.54) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.