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Finding the Fourth Proportional to 810.95, 1,119.68 and 645.56

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Solution

The fourth proportional to 810.95, 1,119.68 and 645.56 is: 891.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.95 : 1,119.68 = 645.56 : x
  2. Step 2: Convert to fraction form
    810.95/1,119.68 = 645.56/x
  3. Step 3: Cross multiply
    810.95x = 1,119.68 × 645.56
  4. Step 4: Simplify right side
    810.95x = 722,820.62
  5. Step 5: Solve for x
    x = 722,820.62/810.95
  6. Step 6: Final answer
    x = 891.33

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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.