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Finding the Fourth Proportional to 970.16, 1,339.61 and 639.23

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Solution

The fourth proportional to 970.16, 1,339.61 and 639.23 is: 882.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    970.16 : 1,339.61 = 639.23 : x
  2. Step 2: Convert to fraction form
    970.16/1,339.61 = 639.23/x
  3. Step 3: Cross multiply
    970.16x = 1,339.61 × 639.23
  4. Step 4: Simplify right side
    970.16x = 856,309.01
  5. Step 5: Solve for x
    x = 856,309.01/970.16
  6. Step 6: Final answer
    x = 882.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.