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Finding the Fourth Proportional to 811.79, 1,118.72 and 578.51

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Solution

The fourth proportional to 811.79, 1,118.72 and 578.51 is: 797.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.79 : 1,118.72 = 578.51 : x
  2. Step 2: Convert to fraction form
    811.79/1,118.72 = 578.51/x
  3. Step 3: Cross multiply
    811.79x = 1,118.72 × 578.51
  4. Step 4: Simplify right side
    811.79x = 647,187.81
  5. Step 5: Solve for x
    x = 647,187.81/811.79
  6. Step 6: Final answer
    x = 797.24

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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.