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Finding the Fourth Proportional to 870.25, 1,303.94 and 639.23

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Solution

The fourth proportional to 870.25, 1,303.94 and 639.23 is: 957.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.25 : 1,303.94 = 639.23 : x
  2. Step 2: Convert to fraction form
    870.25/1,303.94 = 639.23/x
  3. Step 3: Cross multiply
    870.25x = 1,303.94 × 639.23
  4. Step 4: Simplify right side
    870.25x = 833,516.38
  5. Step 5: Solve for x
    x = 833,516.38/870.25
  6. Step 6: Final answer
    x = 957.79

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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.