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Finding the Fourth Proportional to 978.60, 1,348.41 and 808.66

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Solution

The fourth proportional to 978.60, 1,348.41 and 808.66 is: 1,114.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.60 : 1,348.41 = 808.66 : x
  2. Step 2: Convert to fraction form
    978.60/1,348.41 = 808.66/x
  3. Step 3: Cross multiply
    978.60x = 1,348.41 × 808.66
  4. Step 4: Simplify right side
    978.60x = 1,090,405.23
  5. Step 5: Solve for x
    x = 1,090,405.23/978.60
  6. Step 6: Final answer
    x = 1,114.25

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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.