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Finding the Fourth Proportional to 970.21, 1,339.01 and 621.91

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Solution

The fourth proportional to 970.21, 1,339.01 and 621.91 is: 858.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    970.21 : 1,339.01 = 621.91 : x
  2. Step 2: Convert to fraction form
    970.21/1,339.01 = 621.91/x
  3. Step 3: Cross multiply
    970.21x = 1,339.01 × 621.91
  4. Step 4: Simplify right side
    970.21x = 832,743.71
  5. Step 5: Solve for x
    x = 832,743.71/970.21
  6. Step 6: Final answer
    x = 858.31

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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.