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Finding the Fourth Proportional to 2.91, 4 and 2.90

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Solution

The fourth proportional to 2.91, 4 and 2.90 is: 3.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.91 : 4 = 2.90 : x
  2. Step 2: Convert to fraction form
    2.91/4 = 2.90/x
  3. Step 3: Cross multiply
    2.91x = 4 × 2.90
  4. Step 4: Simplify right side
    2.91x = 11.60
  5. Step 5: Solve for x
    x = 11.60/2.91
  6. Step 6: Final answer
    x = 3.99

Related Problems

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Double scale
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Similar ratio
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.