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Finding the Fourth Proportional to 1,290.04, 1,936.40 and 641.20

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Solution

The fourth proportional to 1,290.04, 1,936.40 and 641.20 is: 962.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290.04 : 1,936.40 = 641.20 : x
  2. Step 2: Convert to fraction form
    1,290.04/1,936.40 = 641.20/x
  3. Step 3: Cross multiply
    1,290.04x = 1,936.40 × 641.20
  4. Step 4: Simplify right side
    1,290.04x = 1,241,619.68
  5. Step 5: Solve for x
    x = 1,241,619.68/1,290.04
  6. Step 6: Final answer
    x = 962.47

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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.