Home / 159.90-239.61-78.72

Finding the Fourth Proportional to 159.90, 239.61 and 78.72

Calculator

Solution

The fourth proportional to 159.90, 239.61 and 78.72 is: 117.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.90 : 239.61 = 78.72 : x
  2. Step 2: Convert to fraction form
    159.90/239.61 = 78.72/x
  3. Step 3: Cross multiply
    159.90x = 239.61 × 78.72
  4. Step 4: Simplify right side
    159.90x = 18,862.10
  5. Step 5: Solve for x
    x = 18,862.10/159.90
  6. Step 6: Final answer
    x = 117.96

Related Problems

Find fourth proportional to 79.95, 119.81 and 39.36
Half scale
Find fourth proportional to 319.80, 479.22 and 157.44
Double scale
Find fourth proportional to 160.90, 241.11 and 79.72
Similar ratio
Find fourth proportional to 239.85, 359.42 and 118.08
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.