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Finding the Fourth Proportional to 870.49, 1,304.80 and 639.03

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Solution

The fourth proportional to 870.49, 1,304.80 and 639.03 is: 957.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.49 : 1,304.80 = 639.03 : x
  2. Step 2: Convert to fraction form
    870.49/1,304.80 = 639.03/x
  3. Step 3: Cross multiply
    870.49x = 1,304.80 × 639.03
  4. Step 4: Simplify right side
    870.49x = 833,806.34
  5. Step 5: Solve for x
    x = 833,806.34/870.49
  6. Step 6: Final answer
    x = 957.86

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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.