# need help with statistics

Quiz

1. UMUC Stat Club is sending a delegate of 2 members to attend the 2015 Joint Statistical Meeting in Seattle. There are 10 qualified candidates. How many different ways can the delegate be selected?

**2**. Imagine you are in a game show. There are 4 prizes hidden on a game board with 10 spaces. One prize is worth $100, another is worth $50, and two are worth $10. You have to pay $20 to the host if your choice is not correct. Let the random variable x be the winning. *Show all work. Just the answer, without supporting work, will receive no credit.*

(a) What is your expected winning in this game?

(b) Determine the standard deviation of *x*. (Round the answer to two decimal places)

**3. **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.*

(a) Let X be the number of returns that Mimi gets. As we know, the distribution of X is a binomial probability distribution. What is the number of trials (n), probability of successes (p) and probability of failures (q), respectively? (5 pts)

(b) Find the probability that that she returns at least 1 of the 8 serves from her opponent

(c) How many serves can she expect to return?

Assignment

Using the Excel attachments, open Excel. Open Part 1: BBSalary. You will see average salary, median salary and minimum salary by year from 1969 (B2) to 2002(B35). Follow the following steps:

Step 1: Select “Tools” pull-down menu

Step 2: Choose “Data Analysis”

Step 3: Choose “Descriptive Statistics” from the list of Analysis Tools

Step 4: When the Descriptive Statistics dialog box appears:

Enter B1:B35 in the “Input Range” box

Select “Grouped By Columns”

Select “Labels in First Row”

Select “Output Range”

Enter E1 in the “Output Range” box (to identify the upper left-hand corner of the section of the worksheet where the descriptive statistic will appear)

Click on “Summary Statistics”

Click “OK”

11. If P(A) = 0.3 and P(AUB) = .88 and P(A intersect B) = .12, then P(B)= ?: **.88 = .3 + P(B) – (.12)** solve for P(B)

4. Of five letters (A,B,C,D, and E), two letters are to be selected at random. How many possible selections are there?:

a. 20

b. 7

c. 5!

d. 10

e. 22