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Finding the Fourth Proportional to 872, 1,307.08 and 409.40

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Solution

The fourth proportional to 872, 1,307.08 and 409.40 is: 613.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    872 : 1,307.08 = 409.40 : x
  2. Step 2: Convert to fraction form
    872/1,307.08 = 409.40/x
  3. Step 3: Cross multiply
    872x = 1,307.08 × 409.40
  4. Step 4: Simplify right side
    872x = 535,118.55
  5. Step 5: Solve for x
    x = 535,118.55/872
  6. Step 6: Final answer
    x = 613.67

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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.