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Finding the Fourth Proportional to 1,105.21, 1,657.29 and 643.10

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Solution

The fourth proportional to 1,105.21, 1,657.29 and 643.10 is: 964.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,105.21 : 1,657.29 = 643.10 : x
  2. Step 2: Convert to fraction form
    1,105.21/1,657.29 = 643.10/x
  3. Step 3: Cross multiply
    1,105.21x = 1,657.29 × 643.10
  4. Step 4: Simplify right side
    1,105.21x = 1,065,792.50
  5. Step 5: Solve for x
    x = 1,065,792.50/1,105.21
  6. Step 6: Final answer
    x = 964.33

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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.