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Finding the Fourth Proportional to 1,218.99, 1,680.07 and 971.13

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Solution

The fourth proportional to 1,218.99, 1,680.07 and 971.13 is: 1,338.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,218.99 : 1,680.07 = 971.13 : x
  2. Step 2: Convert to fraction form
    1,218.99/1,680.07 = 971.13/x
  3. Step 3: Cross multiply
    1,218.99x = 1,680.07 × 971.13
  4. Step 4: Simplify right side
    1,218.99x = 1,631,566.38
  5. Step 5: Solve for x
    x = 1,631,566.38/1,218.99
  6. Step 6: Final answer
    x = 1,338.46

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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.