# Stats Library

## Statistics Assignment Library

1. ##### Solved:Suppose the U.S. president wants an estimate of the proportion of the population who support his current policy toward revisions in the health
Suppose the U.S. president wants an estimate of the proportion of the population who support his current policy toward revisions in the health care system. The president wants the estimate to be within 0.03 of the true proportion. Assume a...
2. ##### Solved:The proportion of public accountants who have changed companies within the last three years is to be estimated within 3%. The 90% level of confidence
The proportion of public accountants who have changed companies within the last three years is to be estimated within 3%. The 90% level of confidence is to be used. A study conducted several years ago revealed that the percent of...
3. ##### Solved:A small pilot study is run to compare a new drug for chronic pain to one that is currently available. Participants are
A small pilot study is run to compare a new drug for chronic pain to one that is currently available. Participants are randomly assigned to receive either the new drug or the currently available drug and report improvement in pain...
4. ##### Solved:An observational study is conducted to investigate the association between age and total serum cholesterol. The correlation is estimated at
An observational study is conducted to investigate the association between age and total serum cholesterol. The correlation is estimated at r=0.35. The study involves n=125 participants and mean (std dev) age is 44.3 (10.0) years with an age range of...
5. ##### Solved:The probability that you will win a game is 0.45. (a) If you play the game 80 times, what is the most likely number of wins
The probability that you will win a game is 0.45. (a) If you play the game 80 times, what is the most likely number of wins? (b) What are the mean and variance of a binomial distribution with p =...
6. ##### Solved:It is often assumed that the auto traffic that arrives at the intersection during a unit time period has a Poisson distribution with expected value
It is often assumed that the auto traffic that arrives at the intersection during a unit time period has a Poisson distribution with expected value $m$. Assume that the number of cars $X$ that arrive at an intersection from the...
7. ##### Solved:Let $T$ be the survival time and $T$ follows an exponential distribution.
Let $T$ be the survival time and $T$ follows an exponential distribution. Derive the expression for survival function of $T$. Also obtain expression for force of mortality. Solution Let $T$ be the survival time. The simplest parametric model for survival...
8. ##### Solved:Derive the expression for survival function of $T$,
Derive the expression for survival function of $T$, where $T$ is the survival time having Two parameter weibull distribution. Solution Let the survival time $T$ follows two parameter Weibull distribution. The pdf of $T$ is  \begin{aligned} f(x;\alpha, \beta)&= \begin{cases}...