# 0.2 Practice tests (1-4) and final exams  (Page 30/36)

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41 . As the degrees of freedom increase in an F distribution, the distribution becomes more nearly normal. Histogram F 2 is closer to a normal distribution than histogram F 1, so the sample displayed in histogram F 1 was drawn from the F 3,15 population, and the sample displayed in histogram F 2 was drawn from the F 5,500 population.

42 . Using the calculator function Fcdf, p -value = Fcdf(3.67, 1E, 3,50) = 0.0182. Reject the null hypothesis.

43 . Using the calculator function Fcdf, p -value = Fcdf(4.72, 1E, 4, 100) = 0.0016 Reject the null hypothesis.

## 13.4: test of two variances

44 . The samples must be drawn from populations that are normally distributed, and must be drawn from independent populations.

45 . Let ${\sigma }_{M}^{2}$ = variance in math grades, and ${\sigma }_{E}^{2}$ = variance in English grades.
H 0 : ${\sigma }_{M}^{2}$ ${\sigma }_{E}^{2}$
H a : ${\sigma }_{M}^{2}$ > ${\sigma }_{E}^{2}$

## Practice final exam 1

Use the following information to answer the next two exercises: An experiment consists of tossing two, 12-sided dice (the numbers 1–12 are printed on the sides of each die).

• Let Event A = both dice show an even number.
• Let Event B = both dice show a number more than eight

1 . Events A and B are:

1. mutually exclusive.
2. independent.
3. mutually exclusive and independent.
4. neither mutually exclusive nor independent.

2 . Find P ( A | B ).

1. $\frac{2}{4}$
2. $\frac{16}{144}$
3. $\frac{4}{16}$
4. $\frac{2}{144}$

3 . Which of the following are TRUE when we perform a hypothesis test on matched or paired samples?

1. Sample sizes are almost never small.
2. Two measurements are drawn from the same pair of individuals or objects.
3. Two sample means are compared to each other.
4. Answer choices b and c are both true.

Use the following information to answer the next two exercises: One hundred eighteen students were asked what type of color their bedrooms were painted: light colors, dark colors, or vibrant colors. The results were tabulated according to gender.

Light colors Dark colors Vibrant colors
Female 20 22 28
Male 10 30 8

4 . Find the probability that a randomly chosen student is male or has a bedroom painted with light colors.

1. $\frac{10}{118}\text{}$
2. $\frac{68}{118}\text{}$
3. $\frac{48}{118}\text{}$
4. $\frac{10}{48}\text{}$

5 . Find the probability that a randomly chosen student is male given the student’s bedroom is painted with dark colors.

1. $\frac{30}{118}\text{}$
2. $\frac{30}{48}\text{}$
3. $\frac{22}{118}\text{}$
4. $\frac{30}{52}\text{}$

Use the following information to answer the next two exercises: We are interested in the number of times a teenager must be reminded to do his or her chores each week. A survey of 40 mothers was conducted. [link] shows the results of the survey.

x P ( x )
0 $\frac{2}{40}\text{}$
1 $\frac{5}{40}\text{}$
2
3 $\frac{14}{40}\text{}$
4 $\frac{7}{40}\text{}$
5 $\frac{4}{40}\text{}$

6 . Find the probability that a teenager is reminded two times.

1. 8
2. $\frac{8}{40}\text{}$
3. $\frac{6}{40}\text{}$
4. 2

7 . Find the expected number of times a teenager is reminded to do his or her chores.

1. 15
2. 2.78
3. 1.0
4. 3.13

Use the following information to answer the next two exercises: On any given day, approximately 37.5% of the cars parked in the De Anza parking garage are parked crookedly. We randomly survey 22 cars. We are interested in the number of cars that are parked crookedly.

8 . For every 22 cars, how many would you expect to be parked crookedly, on average?

1. 8.25
2. 11
3. 18
4. 7.5

9 . What is the probability that at least ten of the 22 cars are parked crookedly.

1. 0.1263
2. 0.1607
3. 0.2870
4. 0.8393

10 . Using a sample of 15 Stanford-Binet IQ scores, we wish to conduct a hypothesis test. Our claim is that the mean IQ score on the Stanford-Binet IQ test is more than 100. It is known that the standard deviation of all Stanford-Binet IQ scores is 15 points. The correct distribution to use for the hypothesis test is:

1. Binomial
2. Student's t
3. Normal
4. Uniform

I don't get the example
ways of collecting data at least 10 and explain
Example of discrete variable
Gbenga
I am new here, can I get someone to guide up?
alayo
dies outcome is 1, 2, 3, 4, 5, 6 nothing come outside of it. it is an example of discrete variable
jainesh
continue variable is any value value between 0 to 1 it could be 4digit values eg 0.1, 0.21, 0.13, 0.623, 0.32
jainesh
hi
Kachalla
what's up here ... am new here
Kachalla
sorry question a bit unclear...do you mean how do you analyze quantitative data? If yes, it depends on the specific question(s) you set in the beginning as well as on the data you collected. So the method of data analysis will be dependent on the data collecter and questions asked.
Bheka
how to solve for degree of freedom
saliou
Quantitative data is the data in numeric form. For eg: Income of persons asked is 10,000. This data is quantitative data on the other hand data collected for either make or female is qualitative data.
Rohan
*male
Rohan
Degree of freedom is the unconditionality. For example if you have total number of observations n, and you have to calculate variance, obviously you will need mean for that. Here mean is a condition, without which you cannot calculate variance. Therefore degree of freedom for variance will be n-1.
Rohan
data that is best presented in categories like haircolor, food taste (good, bad, fair, terrible) constitutes qualitative data
Bheka
vegetation types (grasslands, forests etc) qualitative data
Bheka
I don't understand how you solved it can you teach me
solve what?
Ambo
mean
Vanarith
What is the end points of a confidence interval called?
lower and upper endpoints
Bheka
Class members write down the average time (in hours, to the nearest half-hour) they sleep per night.
how we make a classes of this(170.3,173.9,171.3,182.3,177.3,178.3,174.175.3)
Sarbaz
6.5
phoenix
11
Shakir
7.5
Ron
why is always lower class bundry used
Caleb
Assume you are in a class where quizzes are 20% of your grade, homework is 20%, exam _1 is 15%,exam _2 is 15%, and the final exam is 20%.Suppose you are in the fifth week and you just found out that you scored a 58/63 on the fist exam. You also know that you received 6/9,8/10,9/9 on the first
quizzes as well as a 9/11,10/10,and 4.5/7 on the first three homework assignment. what is your current grade in the course?
Diamatu
Abdul
if putting y=3x examine that correlation coefficient between x and y=3x is 1.
what is permutation
how to construct a histogram
You have to plot the class midpoint and the frequency
Wydny
ok so you use those two to draw the histogram right.
Amford
yes
Wydny
ok can i be a friend so you can be teaching me small small
Amford
how do you calculate cost effectiveness?
George
Hi everyone, this is a very good statistical group and am glad to be part of it. I'm just not sure how did I end up here cos this discussion just popes on my screen so if I wanna ask something in the future, how will I find you?
Bheka
To make a histogram, follow these steps: On the vertical axis, place frequencies. Label this axis "Frequency". On the horizontal axis, place the lower value of each interval. ... Draw a bar extending from the lower value of each interval to the lower value of the next interval.
Divya
I really appreciate that
I want to test linear regression data such as maintenance fees vs house size. Can I use R square, F test to test the relationship? Is the good condition of R square greater than 0.5
yes of course must have use f test and also use t test individually multple coefficients
rishi
Alright
umar
hi frnd I'm akeem by name, I wanna study economics and statistics wat ar d thing I must do to b a great economist
akeem
Is R square cannot analysis linear regression of X vs Y relationship?
Mok
To be an economist you have to be professional in maths
umar
hi frnds
Shehu
what is random sampling what is sample error
@Nistha Kashyap Random sampling is the selection of random items (or random numbers) from the group. A sample error occurs when the selected samples do not truely represent the whole group. The can happen when most or all of the selected samples are taken from only one section of the group;
Ron
Thus the sample is not truely random.
Ron
What is zero sum game?
A game in which there is no profit & no loss to any of the both player.
Milan