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Finding the Fourth Proportional to 886.32, 1,328.50 and 643.90

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Solution

The fourth proportional to 886.32, 1,328.50 and 643.90 is: 965.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    886.32 : 1,328.50 = 643.90 : x
  2. Step 2: Convert to fraction form
    886.32/1,328.50 = 643.90/x
  3. Step 3: Cross multiply
    886.32x = 1,328.50 × 643.90
  4. Step 4: Simplify right side
    886.32x = 855,421.15
  5. Step 5: Solve for x
    x = 855,421.15/886.32
  6. Step 6: Final answer
    x = 965.14

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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.