ASSESSMENT STRATEGY

The following Leaning Outcomes will be assessed in the coursework:

1. summarise data and present it in a useful form.
2. to use appropriate distributions in solving a given problem
3. understand the nature of a hypothesis test
4. construct confidence intervals and hypothesis tests for the mean of a single population
5. use an appropriate statistical software package for basic statistical analysis and presentation of data
   Q1. (40% )
   According to an article published in Reader’s Digest , 20% of people are left-handed. For 20 people selected at random, let X denote the number of people out of 20 who are left-handed.
   1. Calculate the probability that exactly four of the twenty are left-handed.
   2. Calculate the probability that less than 8 of the 20 are left-handed.
   3. Find the number of people who are left-handed such that the probability of being less than or equal to this number is about 0.8.
   4. Graph the probability distribution of X.
   5. On your printout, with a pencil, circle the value that Minitab gave you for the probability that less than 8 of the 20 would be left-handed.
   6. On your printout, with a pencil, put a star next to the value that Minitab gave you for the probability that exactly 4 of 20 would be left-handed.
   7. On your printout, with a pencil, underline the value that Minitab gave you for the number of people who are left-handed such that the probability of being less than or equal to this number is about 0.8.

Q2. (60% )

Suppose a reference librarian selected a random sample of 30 customers before starting a new information retrieval system. The retrieval times in minutes are given below.

Information Retrieval

10 15 15 10 20 15 10 20 30 15

25 5 45 22 10 27 25 22 10 30

15 5 8 15 5 36 23 17 15 10

1. Draw a histogram to summarise the retrieval times.
2. Test for normality.
   Minitab has a normality test for determining whether a set of data is randomly selected from a Normal population. Steps are:
   Stat > Basic Statistics > Normality Test
   Variable: Select ‘ column that stores the retrieval times ’
   Title: Enter a Title OK
   Interpret the p-Value in the normality test.
   [Use Minitab HELP if necessary.]
3. Construct a 95% confident interval to estimate the mean retrieval time. Interpret the confidence interval.
4. Does the sample provide sufficient evidence to conclude that mean retrieval time differs from 20 minutes? Use α = 0.05.
5. Interpret the P-value of the test.
6. On your printout, with a pencil, circle the p-Value in the normality test that Minitab gave you (i.e. the P value in part (b)).
7. On your printout, with a pencil, circle the null and alternative hypotheses that Minitab gave you.
8. On your printout, with a pencil, put a star next to the p-value that Minitab gave you (i.e. the P Value in part (e)).
9. On your printout, with a pencil, underline the 95% confidence interval that Minitab gave you.
10. Type your answers and comments to parts (b) – (e) above on a separate sheet of paper.

Submit your coursework in the order listed under Course Work Guidelines above. Make sure that your submission includes ALL graphs created.

Price: $18.58

Solution: The downloadable solution consists of 11 pages, 758 words and 17 charts.
Deliverable: Word Document