Qnt Week 1 Exercizes

Exercise 80 (Ch. 3)

Explain why the times are a population.

      The wait times are a population because it represents a relevant variable with a tangible data set, i.e. we can manipulate the data to make determinations.

Find the mean and median of the times.

      The mean of a population is defined as the sum of all the values in a population divided by the total number of values in the population.

      Sum = 1021 minutes
      Number of values = 25
      Mean = 40.85 minutes

      The median of a population is the midpoint of the values after they have been ordered from the smallest to largest or the largest to the smallest.

      Median = 39 minutes

Find the range and the standard deviation of the times.

      The range is the minimum to maximum values of a data set.

Range = 23 – 67 minutes

      The standard deviation is the square root of the variance, which is the arithmetic mean of the squared deviations from the mean

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Exercise 36 (Ch. 5)

Given:
      80% of students will complete assigned problems
      90% of students completing problems will pass the course
      60% of students not completing problems will pass the course
      Mike took the course last semester and received a passing grade

Find:
The probability that Mike completed the assignments.

Solution:
      We are already given the solution to the question: “What is the probability that Mike passed the course”, which can be rephrased as “What is the probability of passing the course.” This solution would require the analysis of the events:

    1. Completed assignments and passed
    2. Did not complete assignments and passed

      Since the information is provided, the perception of the probability for Mike is 1. We know that Mike passed.

      The probability determination can be reworded as:

    1. Given a passing grade, what is the probability of the event: completed assignments?

      This means that the...