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Finding the Fourth Proportional to 1,090.61, 1,505.07 and 642.51

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Solution

The fourth proportional to 1,090.61, 1,505.07 and 642.51 is: 886.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,090.61 : 1,505.07 = 642.51 : x
  2. Step 2: Convert to fraction form
    1,090.61/1,505.07 = 642.51/x
  3. Step 3: Cross multiply
    1,090.61x = 1,505.07 × 642.51
  4. Step 4: Simplify right side
    1,090.61x = 967,016.61
  5. Step 5: Solve for x
    x = 967,016.61/1,090.61
  6. Step 6: Final answer
    x = 886.67

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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.