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Finding the Fourth Proportional to 1,309.51, 1,807.19 and 720.05

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Solution

The fourth proportional to 1,309.51, 1,807.19 and 720.05 is: 993.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309.51 : 1,807.19 = 720.05 : x
  2. Step 2: Convert to fraction form
    1,309.51/1,807.19 = 720.05/x
  3. Step 3: Cross multiply
    1,309.51x = 1,807.19 × 720.05
  4. Step 4: Simplify right side
    1,309.51x = 1,301,254.52
  5. Step 5: Solve for x
    x = 1,301,254.52/1,309.51
  6. Step 6: Final answer
    x = 993.70

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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.