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Finding the Fourth Proportional to 987.48, 1,479.06 and 661.32

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Solution

The fourth proportional to 987.48, 1,479.06 and 661.32 is: 990.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.48 : 1,479.06 = 661.32 : x
  2. Step 2: Convert to fraction form
    987.48/1,479.06 = 661.32/x
  3. Step 3: Cross multiply
    987.48x = 1,479.06 × 661.32
  4. Step 4: Simplify right side
    987.48x = 978,131.96
  5. Step 5: Solve for x
    x = 978,131.96/987.48
  6. Step 6: Final answer
    x = 990.53

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.