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Finding the Fourth Proportional to 1,386.89, 2,079.12 and 521.81

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Solution

The fourth proportional to 1,386.89, 2,079.12 and 521.81 is: 782.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,386.89 : 2,079.12 = 521.81 : x
  2. Step 2: Convert to fraction form
    1,386.89/2,079.12 = 521.81/x
  3. Step 3: Cross multiply
    1,386.89x = 2,079.12 × 521.81
  4. Step 4: Simplify right side
    1,386.89x = 1,084,902.03
  5. Step 5: Solve for x
    x = 1,084,902.03/1,386.89
  6. Step 6: Final answer
    x = 782.26

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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.