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Finding the Fourth Proportional to 65.80, 91 and 65.08

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Solution

The fourth proportional to 65.80, 91 and 65.08 is: 90.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.80 : 91 = 65.08 : x
  2. Step 2: Convert to fraction form
    65.80/91 = 65.08/x
  3. Step 3: Cross multiply
    65.80x = 91 × 65.08
  4. Step 4: Simplify right side
    65.80x = 5,922.28
  5. Step 5: Solve for x
    x = 5,922.28/65.80
  6. Step 6: Final answer
    x = 90.00

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.