Assignment 1

3. The distribution of undergraduate grade point averages at a large university is approximately normal with a mean of 2.8 and a standard deviation of 0.4.

2) Compute the standard deviation for each of the four samples. Does the assumption of .21 for the population standard deviation appear reasonable?

We know that +/- 1.96 standard deviations from the mean will contain 95% of the values. So, we can get the standard deviation by:

(21) You took a sample of size 21 from a normal distribution with a known standard deviation, . In order to find a 90% confidence interval for the mean, You need to find.

6. Based on questions 3, 4, and 5 is the mean or median a better estimate for the parameter of interest? Explain your reasoning.

6. Based on questions 3, 4, and 5 is the mean or median a better estimate for the parameter of interest? Explain your reasoning.

Question 4: The mode is the most frequently occurring value in a set of data so here the mode is 178 so the answer is e.

2. For the following set of scores, fill in the cells. The mean is 74.13 and the standard deviation is 9.98.

4. a) An example of statistics is the statement “Between the ages of 15 and 24, they take their lives five times as often.”

. Provide examples of variable that are at the nominal, ordinal, interval and ratio level of measurement. Explain why.

is correct. For students who guess at all answers, find the standard deviation for the number of

For each of the four items listed. Indicate whether the variable is categorical or numerical. If it is numerical. Is it discrete or continuous?

| What is the relative frequency of the 0 up to 5 class? (Round your

8. An example will be when customers prefer men employee more than women employee at a department store.

A) $1B) $2C) $0.50D) $0.25Answer: AUse the following to answer 24-27The discrete random variable X is the number of students that show up for Professor Smith's office hours on Monday afternoons. The table below shows the probability distribution for X24. What is the E(X) for this distribution?A) 0B) 1C) 1.5D) 2Answer: BE ( X ) = 0 * .40 + 1 *.30 + 2 *.20 + 3*.10= .30 +.40 +.30= 125. What is the probability that at least 1 student comes to office hours on any given Monday?A) .30B) .40C) .50D) .60Answer: DP ( X ≥ 1 ) = P ( X = 1) + P ( X = 2 ) + P ( X = 3)= .30 +.20 +.10= 0.6026. What is the probability that fewer than 2 students come to office hours on any given