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Finding the Fourth Proportional to 990.01, 1,485.15 and 412.75

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Solution

The fourth proportional to 990.01, 1,485.15 and 412.75 is: 619.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.01 : 1,485.15 = 412.75 : x
  2. Step 2: Convert to fraction form
    990.01/1,485.15 = 412.75/x
  3. Step 3: Cross multiply
    990.01x = 1,485.15 × 412.75
  4. Step 4: Simplify right side
    990.01x = 612,995.66
  5. Step 5: Solve for x
    x = 612,995.66/990.01
  6. Step 6: Final answer
    x = 619.18

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1.5x scale

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.