Home / 97.79-134.81-78.18

Finding the Fourth Proportional to 97.79, 134.81 and 78.18

Calculator

Solution

The fourth proportional to 97.79, 134.81 and 78.18 is: 107.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    97.79 : 134.81 = 78.18 : x
  2. Step 2: Convert to fraction form
    97.79/134.81 = 78.18/x
  3. Step 3: Cross multiply
    97.79x = 134.81 × 78.18
  4. Step 4: Simplify right side
    97.79x = 10,539.64
  5. Step 5: Solve for x
    x = 10,539.64/97.79
  6. Step 6: Final answer
    x = 107.78

Related Problems

Find fourth proportional to 48.90, 67.41 and 39.09
Half scale
Find fourth proportional to 195.59, 269.63 and 156.36
Double scale
Find fourth proportional to 98.79, 136.19 and 79.18
Similar ratio
Find fourth proportional to 146.69, 202.22 and 117.27
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.