Finding the Fourth Proportional to 90.78, 136.20 and 48
Calculator
Solution
The fourth proportional to 90.78, 136.20 and 48 is: 72.02
Step by Step Solution
- Step 1: Write the proportion equation
90.78 : 136.20 = 48 : x - Step 2: Convert to fraction form
90.78/136.20 = 48/x - Step 3: Cross multiply
90.78x = 136.20 × 48 - Step 4: Simplify right side
90.78x = 6,537.60 - Step 5: Solve for x
x = 6,537.60/90.78 - Step 6: Final answer
x = 72.02
Related Problems
Find fourth proportional to 45.39, 68.10 and 24
Half scale
Find fourth proportional to 181.56, 272.40 and 96
Double scale
Find fourth proportional to 91.78, 137.70 and 49
Similar ratio
Find fourth proportional to 136.17, 204.30 and 72
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.