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Finding the Fourth Proportional to 1,215.50, 1,677.40 and 663.50

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Solution

The fourth proportional to 1,215.50, 1,677.40 and 663.50 is: 915.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,215.50 : 1,677.40 = 663.50 : x
  2. Step 2: Convert to fraction form
    1,215.50/1,677.40 = 663.50/x
  3. Step 3: Cross multiply
    1,215.50x = 1,677.40 × 663.50
  4. Step 4: Simplify right side
    1,215.50x = 1,112,954.90
  5. Step 5: Solve for x
    x = 1,112,954.90/1,215.50
  6. Step 6: Final answer
    x = 915.64

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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.