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Finding the Fourth Proportional to 802.78, 1,106.50 and 645.16

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Solution

The fourth proportional to 802.78, 1,106.50 and 645.16 is: 889.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    802.78 : 1,106.50 = 645.16 : x
  2. Step 2: Convert to fraction form
    802.78/1,106.50 = 645.16/x
  3. Step 3: Cross multiply
    802.78x = 1,106.50 × 645.16
  4. Step 4: Simplify right side
    802.78x = 713,869.54
  5. Step 5: Solve for x
    x = 713,869.54/802.78
  6. Step 6: Final answer
    x = 889.25

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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.