Download STAT210 quiz2 Fall04 - University of South Alabama

STAT210 quiz2 Fall04 (Solution)
Consider the following stem and leaf display
Stem leaves
3
0,3,7
4
2,4,6,6
5
0,7,8
Answer the following questions based of this display
1. List all the data values which are used to prepare this display
Answer: 30, 33, 37, 42, 44, 46, 46, 50, 57, 58
2. what is maximum value in this data set?
Answer: 58
3. what is the minimum value in this dataet?
Answer: 30
Answer the following questions
4. List two names of measures of central tendency.
Possible answers: mean, mode, median, trimmed mean
5. What measure of central tendency should be used when outliers are present in
data?
Answer: Median
Stat210 Quiz3Fall04
1. A summary measure calculated for the population data is called
a. population parameter b. sample statistic c. an outlier
Answer: population parameter
2. A summary measure calculated for the sample data is called
a. population parameter b. sample statistic c. an outlier
Answer: sample statistics
3. Chebyshev’s rule can be applied to
a. any distribution b. bell-shaped distributions only c. skewed distributions only
Answer: any distribution
4. Empirical rule can be applied to
a. any distribution b. bell-shaped distributions only c. skewed distributions only
Answer: bell-shaped distributions only
5. 50th percentile is median (T / F)
Answer: True
Stat210 Quiz4 Fall04
1. The method of assigning the probabilitites to outcomes of an experiment with
equally likely outcomes is called classical rule .
2. When the outcomes of an experiment are not equally likely then we use relative
frequency approach to assign the probabilities to different events.
3. State the law of large numbers.
As the number of times experiment repeated (n) increases, the approximate
probability (assigned through relative frequency approach) approaches to its true
value.
4. A random experiment consists of determining the gender and smoking status of a
person. What are the possible outcomes of this experiment. List them.
S = { (F, smoker) (F, non-smoker), (M, smoker), (M, nonsmoker)}
5. An experiment consists of tossing two coins and rolling a die, how many possible
outcomes of this experiment? ( 12 / 24/ 36/ 64)
Quiz 5 Stat 210
Fall 04
Consider the following table of numbers in two columns
x
P(x)
0
.30
1
.50
2
.20
1. Verify if these two columns define a probability distribution of x.
Since each entry of P(x) is positive and sum of all P(X) is 1, Yes it is probability
distrituition
2. What is the probability that x takes value at the most 1.
P(x≤1) = P(x=0) + P(x=1) = .30+.50 = .80
3. What is the probability that x takes value at least 1.
P(x≥ 1) = P(x=1)+P(x=2) = .50+.20 = .70
4. Read the following problem carefully and write the parameters of the binomial distribution.
At the Express House Delivery Service, providing high quality service to the customers is the top
priority of the management. The company guarantees a refund of all charges if a package it is delivering
does not arrive at its destination by the specified time. It is known from past data that despite all efforts,
2% of packages mailed through this company do not arrive at their destination within specified time.
Suppose a corporation mails 10 packages through Express delivery Service on a certain day. And
binomial variate is x = # packages that arrive late in a group of 10 packages.
n = 10, p = .02
5. In the problem in question 4, in long run, what is the average number of packages
that arrive late ? what is the variance of x in question 4?
Average = n*p = 10*.02 = .2 Variance = n*p*(1-p) = 10*.02*.98 = .196