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Finding the Fourth Proportional to 1,980.21, 2,970.65 and 810.84

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Solution

The fourth proportional to 1,980.21, 2,970.65 and 810.84 is: 1,216.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,980.21 : 2,970.65 = 810.84 : x
  2. Step 2: Convert to fraction form
    1,980.21/2,970.65 = 810.84/x
  3. Step 3: Cross multiply
    1,980.21x = 2,970.65 × 810.84
  4. Step 4: Simplify right side
    1,980.21x = 2,408,721.85
  5. Step 5: Solve for x
    x = 2,408,721.85/1,980.21
  6. Step 6: Final answer
    x = 1,216.40

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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.