Home / 121-181.50-45

Finding the Fourth Proportional to 121, 181.50 and 45

Calculator

Solution

The fourth proportional to 121, 181.50 and 45 is: 67.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    121 : 181.50 = 45 : x
  2. Step 2: Convert to fraction form
    121/181.50 = 45/x
  3. Step 3: Cross multiply
    121x = 181.50 × 45
  4. Step 4: Simplify right side
    121x = 8,167.50
  5. Step 5: Solve for x
    x = 8,167.50/121
  6. Step 6: Final answer
    x = 67.50

Related Problems

Find fourth proportional to 60.50, 90.75 and 22.50
Half scale
Find fourth proportional to 242, 363 and 90
Double scale
Find fourth proportional to 122, 183 and 46
Similar ratio
Find fourth proportional to 181.50, 272.25 and 67.50
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.