Stats Library

Statistics Assignment Library

  1. Solved:If electricity power failures occur according to a Poisson distribution with an average of 3 failures
    If electricity power failures occur according to a Poisson distribution with an average of 3 failures every twenty weeks, calculate the probability that there will not be more than one failure during a particular week. Solution Let $X$ denote the...
  2. Solved:A consulting engineer receives on average 0.7 requests per week. Find the probability that
    A consulting engineer receives on average 0.7 requests per week. Find the probability that a) In a given week, there will be at least one request; b) In a given 4 week period there will be at least 3 requests....
  3. Solved:The actual amount of coffee (in grams) in a 230-gram jar filled by a certain machine
    The actual amount of coffee (in grams) in a 230-gram jar filled by a certain machine is a random variable whose probability density is given by $$ \begin{aligned} f(x)=\left\{ \begin{array}{ll} 0 & \hbox{$x \leq 227.5$;}\\ \frac{1}{5} , & \hbox{$227.5 <...
  4. Solved:The price for a gallon of whole milk is uniformly distributed between
    The price for a gallon of whole milk is uniformly distributed between \$2.25 and \$2.75 during July in the U.S. Give the equation and graph the pdf for X, the price per gallon of whole milk during July. Also determine...
  5. Solved:Dottie’s Tax Service specializes in federal tax returns for professional clients, such as physicians
    Dottie's Tax Service specializes in federal tax returns for professional clients, such as physicians, dentists, accountants, and lawyers. A recent audit by the IRS of the returns she prepared indicated that an error was made on 11% of the returns...
  6. Solved:The breaking strengths (say, y) for one-foot- square samples of a particular synthetic fabric are approximately normally
    The breaking strengths (say, y) for one-foot- square samples of a particular synthetic fabric are approximately normally distributed with a mean of 2,280 pounds per square inch (psi) and a standard deviation of 10.6 psi. a. Find the probability of...
  7. Solved:If 37% of high school students said that they exercise regularly, find the probability that 5 randomly selected
    If 37% of high school students said that they exercise regularly, find the probability that 5 randomly selected high school students will say that they exercise regularly. Would you consider this event likely or unlikely to occur? Explain your answer....
  8. Solved:Let $X$ be a random variable of the continuous type with pdf given by
    Let $X$ be a random variable of the continuous type with pdf given by: $$ \begin{aligned} f(x)& = \frac{1}{7}e^{-x/7}\\ &\qquad \text{ for }x > 0 \end{aligned} $$ Use the cdf of $X$ to determine the median of the distribution. Solution...
  9. Solved:The GRE is widely used to help predict the performance of applicants to graduate schools. The range of possible scores on a GRE
    The GRE is widely used to help predict the performance of applicants to graduate schools. The range of possible scores on a GRE is 200 to 900. The psychology department at a university finds that the students in their department...
  10. Solved:The Mental Development Index (MDI) of the Bayley Scales of Infant Development is a standardized measure used in longitudinal follow-up
    The Mental Development Index (MDI) of the Bayley Scales of Infant Development is a standardized measure used in longitudinal follow-up of high-risk infants. The scores on the MDI have approximately a normal distribution with a mean of 100 and standard...