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Finding the Fourth Proportional to 881.40, 1,216.53 and 645.69

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Solution

The fourth proportional to 881.40, 1,216.53 and 645.69 is: 891.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    881.40 : 1,216.53 = 645.69 : x
  2. Step 2: Convert to fraction form
    881.40/1,216.53 = 645.69/x
  3. Step 3: Cross multiply
    881.40x = 1,216.53 × 645.69
  4. Step 4: Simplify right side
    881.40x = 785,501.26
  5. Step 5: Solve for x
    x = 785,501.26/881.40
  6. Step 6: Final answer
    x = 891.20

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Double scale
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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.