Home / 115.79-159.59-80.72

Finding the Fourth Proportional to 115.79, 159.59 and 80.72

Calculator

Solution

The fourth proportional to 115.79, 159.59 and 80.72 is: 111.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.79 : 159.59 = 80.72 : x
  2. Step 2: Convert to fraction form
    115.79/159.59 = 80.72/x
  3. Step 3: Cross multiply
    115.79x = 159.59 × 80.72
  4. Step 4: Simplify right side
    115.79x = 12,881.51
  5. Step 5: Solve for x
    x = 12,881.51/115.79
  6. Step 6: Final answer
    x = 111.25

Related Problems

Find fourth proportional to 57.90, 79.80 and 40.36
Half scale
Find fourth proportional to 231.59, 319.19 and 161.43
Double scale
Find fourth proportional to 116.79, 160.97 and 81.72
Similar ratio
Find fourth proportional to 173.69, 239.39 and 121.07
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.