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Finding the Fourth Proportional to 690.85, 1,025.59 and 661.69

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Solution

The fourth proportional to 690.85, 1,025.59 and 661.69 is: 982.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.85 : 1,025.59 = 661.69 : x
  2. Step 2: Convert to fraction form
    690.85/1,025.59 = 661.69/x
  3. Step 3: Cross multiply
    690.85x = 1,025.59 × 661.69
  4. Step 4: Simplify right side
    690.85x = 678,622.65
  5. Step 5: Solve for x
    x = 678,622.65/690.85
  6. Step 6: Final answer
    x = 982.30

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.