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

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26 . In a survey of 80 males, 45 had played an organized sport growing up. Of the 70 females surveyed, 25 had played an organized sport growing up. We are interested in whether the proportion for males is higher than the proportion for females. The correct conclusion is that:

1. there is insufficient information to conclude that the proportion for males is the same as the proportion for females.
2. there is insufficient information to conclude that the proportion for males is not the same as the proportion for females.
3. there is sufficient evidence to conclude that the proportion for males is higher than the proportion for females.
4. not enough information to make a conclusion.

27 . From past experience, a statistics teacher has found that the average score on a midterm is 81 with a standard deviation of 5.2. This term, a class of 49 students had a standard deviation of 5 on the midterm. Do the data indicate that we should reject the teacher’s claim that the standard deviation is 5.2? Use α = 0.05.

1. Yes
2. No
3. Not enough information given to solve the problem

28 . Three loading machines are being compared. Ten samples were taken for each machine. Machine I took an average of 31 minutes to load packages with a standard deviation of two minutes. Machine II took an average of 28 minutes to load packages with a standard deviation of 1.5 minutes. Machine III took an average of 29 minutes to load packages with a standard deviation of one minute. Find the p -value when testing that the average loading times are the same.

1. p -value is close to zero
2. p -value is close to one
3. not enough information given to solve the problem

Use the following information to answer the next three exercises: A corporation has offices in different parts of the country. It has gathered the following information concerning the number of bathrooms and the number of employees at seven sites:

 Number of employees x 650 730 810 900 102 107 1150 Number of bathrooms y 40 50 54 61 82 110 121

29 . Is the correlation between the number of employees and the number of bathrooms significant?

1. Yes
2. No
3. Not enough information to answer question

30 . The linear regression equation is:

1. ŷ = 0.0094 − 79.96 x
2. ŷ = 79.96 + 0.0094 x
3. ŷ = 79.96 − 0.0094 x
4. ŷ = − 0.0094 + 79.96 x

31 . If a site has 1,150 employees, approximately how many bathrooms should it have?

1. 69
2. 91
3. 91,954
4. We should not be estimating here.

32 . Suppose that a sample of size ten was collected, with $\overline{x}$ = 4.4 and s = 1.4. H 0 : σ 2 = 1.6 vs. H a : σ 2 ≠ 1.6. Which graph best describes the results of the test?

Sixty-four backpackers were asked the number of days since their latest backpacking trip. The number of days is given in [link] :

 # of days 1 2 3 4 5 6 7 8 Frequency 5 9 6 12 7 10 5 10

33 . Conduct an appropriate test to determine if the distribution is uniform.

1. The p -value is>0.10. There is insufficient information to conclude that the distribution is not uniform.
2. The p -value is<0.01. There is sufficient information to conclude the distribution is not uniform.
3. The p -value is between 0.01 and 0.10, but without alpha ( α ) there is not enough information
4. There is no such test that can be conducted.

34 . Which of the following statements is true when using one-way ANOVA?

1. The populations from which the samples are selected have different distributions.
2. The sample sizes are large.
3. The test is to determine if the different groups have the same means.
4. There is a correlation between the factors of the experiment.

Solutions

1 . b. parameter.

2 . a.

3 . c. seven

4 . c. 0.02

5 . c. none of the above

6 . d. $\frac{100}{140}$

7 . a. ≈ 0

8 . b. The values for x are: {1, 2, 3,..., 14}

9 . c. 0.9417.

10 . d. binomial

11 . d. 8.7

12 . a. –1.96

13 . a. 0.6321

14 . d. 360

15 . b. $N\left(72,\frac{72}{\sqrt{50}}\right)$

16 . a. $\frac{3}{9}$

17 . d.

18 . b. 5.5

19 . d. 6.92

20 . a. 5

21 . b. 0.8541

22 . b. 0.2

23 . a. –1.

24 . c. matched pairs, dependent groups.

25 . d. Reject H 0 . There is sufficient evidence to conclude that there is a difference in the mean scores.

26 . c. there is sufficient evidence to conclude that the proportion for males is higher than the proportion for females.

27 . b. no

28 . b. p -value is close to 1.

29 . b. No

30 . c. $\stackrel{^}{y}$ = 79.96 x – 0.0094

31 . d. We should not be estimating here.

32 . a.

33 . a. The p -value is>0.10. There is insufficient information to conclude that the distribution is not uniform.

34 . c. The test is to determine if the different groups have the same means.

discuss the roles of vital and health statistic in the planning of health service of the community
given that the probability of
BITRUS
can man city win Liverpool ?
There are two coins on a table. When both are flipped, one coin land on heads eith probability 0.5 while the other lands on head with probability 0.6. A coin is randomly selected from the table and flipped. (a) what is probability it lands on heads? (b) given that it lands on tail, what is the Condi
0.5*0.5+0.5*0.6
Ravasz
It should be a Machine learning terms。
Mok
it is a term used in linear regression
Saurav
what are the differences between standard deviation and variancs?
Enhance
what is statistics
statistics is the collection and interpretation of data
Enhance
the science of summarization and description of numerical facts
Enhance
Is the estimation of probability
Zaini
mr. zaini..can u tell me more clearly how to calculated pair t test
Haai
do you have MG Akarwal Statistics' book Zaini?
Enhance
Haai how r u?
Enhance
maybe .... mathematics is the science of simplification and statistics is the interpretation of such values and its implications.
Miguel
can we discuss about pair test
Haai
what is outlier?
outlier is an observation point that is distant from other observations.
Gidigah
what is its effect on mode?
Usama
Outlier  have little effect on the mode of a given set of data.
Gidigah
How can you identify a possible outlier(s) in a data set.
Daniel
The best visualisation method to identify the outlier is box and wisker method or boxplot diagram. The points which are located outside the max edge of wisker(both side) are considered as outlier.
Akash
@Daniel Adunkwah - Usually you can identify an outlier visually. They lie outside the observed pattern of the other data points, thus they're called outliers.
Ron
what is completeness?
I am new to this. I am trying to learn.
Dom
I am also new Dom, welcome!
Nthabi
thanks
Dom
please my friend i want same general points about statistics. say same thing
alex
outliers do not have effect on mode
Meselu
also new
yousaf
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.