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Finding the Fourth Proportional to 1,538.70, 2,123.41 and 840.07

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Solution

The fourth proportional to 1,538.70, 2,123.41 and 840.07 is: 1,159.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,538.70 : 2,123.41 = 840.07 : x
  2. Step 2: Convert to fraction form
    1,538.70/2,123.41 = 840.07/x
  3. Step 3: Cross multiply
    1,538.70x = 2,123.41 × 840.07
  4. Step 4: Simplify right side
    1,538.70x = 1,783,812.81
  5. Step 5: Solve for x
    x = 1,783,812.81/1,538.70
  6. Step 6: Final answer
    x = 1,159.30

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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.