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Finding the Fourth Proportional to 1,291.01, 1,780.92 and 870.80

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Solution

The fourth proportional to 1,291.01, 1,780.92 and 870.80 is: 1,201.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,291.01 : 1,780.92 = 870.80 : x
  2. Step 2: Convert to fraction form
    1,291.01/1,780.92 = 870.80/x
  3. Step 3: Cross multiply
    1,291.01x = 1,780.92 × 870.80
  4. Step 4: Simplify right side
    1,291.01x = 1,550,816.23
  5. Step 5: Solve for x
    x = 1,550,816.23/1,291.01
  6. Step 6: Final answer
    x = 1,201.25

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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.