Introductory statistics UE Past Papers Questions.

Briefly explain the following terms.

1. Sample
2. Scatter diagram
3. Mutually exclusive events
4. Interval estimation
5. Type 1 error

Answer / Solution

UNSOLVED

Last year, five randomly selected students took a math aptitude test before they began their statistics course. The table below shows scores on the aptitude test and statistics grades.

Use the table to answer the following questions

1. Regress Y on X and interpret the constant coefficient and slope parameter
2. If a student made an 80 on the aptitude test, what grade would we expect him/her to make in statistics?
3. How well does the regress on the equation fit the data?

Answer / Solution

UNSOLVED

1. X is a random variable such that . Given that and , find the value of n.
2. Let the random variable X represent the number of boys in a family.

1. Construct the probability distribution for a random variable X in a family of three children (assuming that the chance for a boy to be born is  )
2. Show that X is a random variable.
3. Find the expected value and standard deviation of X.

100. The mean number of bacteria per milliliter of liquid is known to be 4. Assuming that the number of bacteria follows a Poisson distribution, find the probability that , in 1 ml of liquid , there will be four bacteria.

Answer / Solution

UNSOLVED

The same test was given to a group 100 scouts and to a group of 144 guides. The mean score for the scouts was 27.53 and the mean score for the guides was 26.81. Assuming a population variance of 12.11 for both scouts scores and guides scores;

1. Construct a 95% confidence interval for the difference between population means of scouts scores and guides scores and interpret the results.
2. Test whether the scout`s performance in the test is the same to that of guides at 5% level of significance, assuming that the scores are normally distributed. Use the general procedures for testing hypothesis.

Answer / Solution

UNSOLVED

Frequency distribution of age at loss of last tooth is given below:

Find

1. Mean
2. Median
3. Mode

Answer / Solution

UNSOLVED