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Finding the Fourth Proportional to 813.75, 1,121.54 and 648.51

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Solution

The fourth proportional to 813.75, 1,121.54 and 648.51 is: 893.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.75 : 1,121.54 = 648.51 : x
  2. Step 2: Convert to fraction form
    813.75/1,121.54 = 648.51/x
  3. Step 3: Cross multiply
    813.75x = 1,121.54 × 648.51
  4. Step 4: Simplify right side
    813.75x = 727,329.91
  5. Step 5: Solve for x
    x = 727,329.91/813.75
  6. Step 6: Final answer
    x = 893.80

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1.5x scale

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.