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Finding the Fourth Proportional to 678.45, 1,017.36 and 245.55

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Solution

The fourth proportional to 678.45, 1,017.36 and 245.55 is: 368.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.45 : 1,017.36 = 245.55 : x
  2. Step 2: Convert to fraction form
    678.45/1,017.36 = 245.55/x
  3. Step 3: Cross multiply
    678.45x = 1,017.36 × 245.55
  4. Step 4: Simplify right side
    678.45x = 249,812.75
  5. Step 5: Solve for x
    x = 249,812.75/678.45
  6. Step 6: Final answer
    x = 368.21

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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.