Stats Library

Statistics Assignment Library

  1. Solved (Free): A committee of three people is to be selected at random from a council consisting of five men and three women
    A committee of three people is to be selected at random from a council consisting of five men and three women. What is the expected number of women on the committee? Solution Council consists of 5 Men and 3 Women....
  2. Solved (Free): As a measure of intelligence, mice are timed when going through a maze to reach a reward of food. The time (in seconds) required for any mouse
    As a measure of intelligence, mice are timed when going through a maze to reach a reward of food. The time (in seconds) required for any mouse is a random variable Y with a density function given by $$ \begin{equation*}...
  3. Solved (Free): It is estimated that 50% of emails are spam emails. Some software has been applied to filter these spam emails before they reach your inbox
    It is estimated that 50% of emails are spam emails. Some software has been applied to filter these spam emails before they reach your inbox. A certain brand of software claims that it can detect 99% of spam emails, and...
  4. Solved (Free): A survey was conducted on a random sample of 1,000 Baltimore residents. Residents were asked whether they have health insurance. 650 individuals surveyed
    A survey was conducted on a random sample of 1,000 Baltimore residents. Residents were asked whether they have health insurance. 650 individuals surveyed said they do have health insurance, and 350 said they do not have health insurance. Find the...
  5. Solved (Free): Richard has just been given a ten-question multiple choice test in his history class. Each question has five answers only one of which is correct
    Richard has just been given a ten-question multiple choice test in his history class. Each question has five answers only one of which is correct. Since Richard has not attended class recently, he does not know any of the answers....
  6. Solved (Free): A certain industrial process is brought down for recalibration whenever the quality of the items produced falls below specifications
    A certain industrial process is brought down for recalibration whenever the quality of the items produced falls below specifications. Let $X$ represents the number of times the process is recalibrated during a week, and assume that $X$ has the following...
  7. Solved (Free): Among companies doing highway or bridge construction, 80% test employees for substance abuse
    Among companies doing highway or bridge construction, 80% test employees for substance abuse (based on data from the Construction Financial Management Association) A study involves the random selection of 12 such companies. (a) Find the probability that exactly 7 of...
  8. Solved (Free): Mimi just started her tennis class three weeks ago. On average, she is able to return 20% of her opponent’s serves
    Mimi just started her tennis class three weeks ago. On average, she is able to return 20% of her opponent's serves. Assume her opponent serves 8 times. Show all work. Just the answer, without supporting work, will receive no credit....
  9. Solved (Free): The American Cancer Society wants to estimate the proportion of high school seniors who smokes regularly. In a random sample of
    The American Cancer Society wants to estimate the proportion of high school seniors who smokes regularly. In a random sample of 1,000 seniors, 200 smoke regularly. Construct 90% confidence interval. Interpret your confidence interval. Solution Given that sample size $n...
  10. Solved (Free): A physician claims that 13.6% of all pregnant females smoke during their pregnancy. A random sample of 400 pregnant women revealed
    A physician claims that 13.6% of all pregnant females smoke during their pregnancy. A random sample of 400 pregnant women revealed that 60 of them are smoking while pregnant. Test the physician's claim at the 0.05 level of significance. Solution...