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Finding the Fourth Proportional to 821.23, 1,133.09 and 489.51

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Solution

The fourth proportional to 821.23, 1,133.09 and 489.51 is: 675.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.23 : 1,133.09 = 489.51 : x
  2. Step 2: Convert to fraction form
    821.23/1,133.09 = 489.51/x
  3. Step 3: Cross multiply
    821.23x = 1,133.09 × 489.51
  4. Step 4: Simplify right side
    821.23x = 554,656.44
  5. Step 5: Solve for x
    x = 554,656.44/821.23
  6. Step 6: Final answer
    x = 675.40

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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.