Exams › GATE › General Aptitude
The lengths of a large stock of titanium rods follow a normal distribution with mean $\mu = 440$ mm and standard deviation $\sigma = 1$ mm. What is the percentage of rods whose lengths are between 438 mm and 441 mm?
- 81.85%
- 68.4%
- 99.75%
- 86.64%
Correct answer: 81.85%
Solution
Standardizing gives $z = (438-440)/1 = -2$ and $z = (441-440)/1 = 1$. The required probability is $P(-2 \le Z \le 1) = P(Z \le 1) - P(Z \le -2) = 0.8413 - 0.0228 = 0.8185$. Thus the percentage is 81.85%.
Related GATE General Aptitude questions
- If $f(x)=2x^7+3x-5$, which of the following is a factor of $f(x)$?
- In a process, the number of cycles to failure decreases exponentially with an increase in load. At a load of 80 units, it takes 100 cycles for failure. When the load is halved, it takes 10,000 cycles for failure. The load for which failure will happen in 5,000 cycles is _________.
- Type I error in hypothesis testing is
- A five-digit number is formed using the digits 1, 3, 5, 7 and 9 without repeating any of them. What is the sum of all such possible five-digit numbers?
- The cost function for a product in a firm is given by \(5q^2\), where \(q\) is the amount of production. The firm can sell the product at a market price of 50 per unit. The number of units to be produced by the firm such that the profit is maximized is
- Consider the equation: $(7526)_8 - (Y)_8 = (4364)_8$, where $(X)_N$ stands for $X$ to the base $N$. Find $Y$.
⚔️ Practice GATE General Aptitude free + battle 1v1 →