Four numbers a, b, c, d are in proportion. If a = 32, b = 72, and c = 180, what is the value of d?
405
Four numbers a, b, c, d are in proportion means \(\dfrac{a}{b} = \dfrac{c}{d}\), so d is the fourth proportional to a, b, c.
Cross-multiplying gives \(a \cdot d = b \cdot c\), hence \(d = \dfrac{b \cdot c}{a}\).
Substitute a = 32, b = 72, c = 180: \(d = \dfrac{72 \times 180}{32} = \dfrac{12960}{32}\).
Divide: \(d = 405\).
Hence, the value of d is 405.
Similar Questions
Find the fourth proportional to the numbers 8, 32 and 17.
If 7, 14.2, 21.7, and x are in proportion, what is the value of x?
Find the fourth proportional to 6, 9, and 15.
In a proportion, the first, second and third proportionals are respectively 6, 24 and 11. If the fourth proportional is \((x^{2} - 7x)\), find the positive value of x.
Find the fourth proportional to 2.5, 4, and 10.
If the fourth proportional to P, 25 and 8 is 4, then find the value of P.
The fourth proportional to three numbers is 36. The first two numbers are 8 and 12. Find the third number.
Find the fourth proportional to 3, 4 and 9.
Find the fourth proportional of \(5\sqrt{3}\), \(4\sqrt{5}\), and \(10\sqrt{3}\).
Find the fourth proportional to 8.6, 10.75, and 6.
Important Questions from Fourth Proportional
Find the fourth proportional of (x4 - y4), (x + y) and (x − y), provided x ≠ y.
What is the fourth proportional to the numbers 8, 66 and 112?
The fourth proportion to 12, 18, 6 is equal to the third proportion to 4, k. What is the value of k?
The fourth proportional to 10, 12, 15 is :
Find the fourth proportion of the following numbers.
\(\frac{1}{3}\) of 18, \(\frac{4}{5}\) of 20, \(\frac{3}{7}\) of 28.
