Home / 117.30-161.82-78.51

Finding the Fourth Proportional to 117.30, 161.82 and 78.51

Calculator

Solution

The fourth proportional to 117.30, 161.82 and 78.51 is: 108.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    117.30 : 161.82 = 78.51 : x
  2. Step 2: Convert to fraction form
    117.30/161.82 = 78.51/x
  3. Step 3: Cross multiply
    117.30x = 161.82 × 78.51
  4. Step 4: Simplify right side
    117.30x = 12,704.49
  5. Step 5: Solve for x
    x = 12,704.49/117.30
  6. Step 6: Final answer
    x = 108.31

Related Problems

Find fourth proportional to 58.65, 80.91 and 39.26
Half scale
Find fourth proportional to 234.60, 323.64 and 157.02
Double scale
Find fourth proportional to 118.30, 163.20 and 79.51
Similar ratio
Find fourth proportional to 175.95, 242.73 and 117.77
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.