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Finding the Fourth Proportional to 636.76, 879.55 and 491.19

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Solution

The fourth proportional to 636.76, 879.55 and 491.19 is: 678.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.76 : 879.55 = 491.19 : x
  2. Step 2: Convert to fraction form
    636.76/879.55 = 491.19/x
  3. Step 3: Cross multiply
    636.76x = 879.55 × 491.19
  4. Step 4: Simplify right side
    636.76x = 432,026.16
  5. Step 5: Solve for x
    x = 432,026.16/636.76
  6. Step 6: Final answer
    x = 678.48

Related Problems

Find fourth proportional to 318.38, 439.78 and 245.60
Half scale
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Double scale
Find fourth proportional to 637.76, 880.93 and 492.19
Similar ratio
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1.5x scale

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.