Home / 115-172.50-69.40

Finding the Fourth Proportional to 115, 172.50 and 69.40

Calculator

Solution

The fourth proportional to 115, 172.50 and 69.40 is: 104.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    115 : 172.50 = 69.40 : x
  2. Step 2: Convert to fraction form
    115/172.50 = 69.40/x
  3. Step 3: Cross multiply
    115x = 172.50 × 69.40
  4. Step 4: Simplify right side
    115x = 11,971.50
  5. Step 5: Solve for x
    x = 11,971.50/115
  6. Step 6: Final answer
    x = 104.10

Related Problems

Find fourth proportional to 57.50, 86.25 and 34.70
Half scale
Find fourth proportional to 230, 345 and 138.80
Double scale
Find fourth proportional to 116, 174 and 70.40
Similar ratio
Find fourth proportional to 172.50, 258.75 and 104.10
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.