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Finding the Fourth Proportional to 1,386.71, 2,080.29 and 647.06

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Solution

The fourth proportional to 1,386.71, 2,080.29 and 647.06 is: 970.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,386.71 : 2,080.29 = 647.06 : x
  2. Step 2: Convert to fraction form
    1,386.71/2,080.29 = 647.06/x
  3. Step 3: Cross multiply
    1,386.71x = 2,080.29 × 647.06
  4. Step 4: Simplify right side
    1,386.71x = 1,346,072.45
  5. Step 5: Solve for x
    x = 1,346,072.45/1,386.71
  6. Step 6: Final answer
    x = 970.69

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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.