Assignment Solutions
The lifetime $X$ of a device is an exponential random variable with mean = $1/R$. Suppose that due to irregularities in the production process, the parameter $R$ is random and…
The useful life of an electrical component is exponentially distributed with a mean of 2,500 hours. a. What is the probability the circuit will last more than 3,000 hours? b.…
The amount of time that a union stays on strike is judged to follow an exponential distribution with a mean of 10 days. a. Find the probability that a strike…
The amount of time it takes a person to be served at a given restaurant is a random variable with the probability density $$ \begin{aligned} f(x) = \frac{1}{4}e^{-\frac{x}{4}}, x>0 \end{aligned}…
The tread wear (in thousands of kilometers) that car owners get with a certain kind of tire is a random variable whose probability density is given by $$ f(x) =…
If the number of minutes that a doctor spends with a patient is a random variable having an exponential distribution with the parameter $\theta = 9$, what are the probabilities…
The amount of time, in hours, that a machine functions before breakdown is a continuous random variable with pdf $$ \begin{aligned} f(t) &= \frac{1}{120} e^{-t/120}, t\geq 0 \end{aligned} $$ What…
The time required to pass through security screening at the airport can be annoying to travelers. The mean wait time during peak periods at Cincinnati/Northern Kentucky International Airport is 12.1…
The number of years a radio functions is exponentially distributed with parameter $\lambda =1/8$. If Jones buys a used radio, what is the probability that it will be working after…
The lifetimes in years for a particular brand of cathode ray tube are exponentially distributed with a mean of 5 years. What percent of the tubes have lifetimes between 5…
