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Finding the Fourth Proportional to 901.50, 1,243.64 and 639.66

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Solution

The fourth proportional to 901.50, 1,243.64 and 639.66 is: 882.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    901.50 : 1,243.64 = 639.66 : x
  2. Step 2: Convert to fraction form
    901.50/1,243.64 = 639.66/x
  3. Step 3: Cross multiply
    901.50x = 1,243.64 × 639.66
  4. Step 4: Simplify right side
    901.50x = 795,506.76
  5. Step 5: Solve for x
    x = 795,506.76/901.50
  6. Step 6: Final answer
    x = 882.43

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1.5x scale

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.