# 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.

what is statistics
statistics is the beach of mathematics which deals with collection ,organisation, presentation, analysis and interpretation of numerical data
Saeed
oh but interpretation of data, like what and how? 🤔
Bhavani
interpretation: Think in a way that you have given a company year turnover and you have a record of 100years and data set is like (Year,Turnover). Now with that data you can interpret many thing how was the company growth, when were the losses and other things
Akash
interpretation: it is a process in which we make a decision about a population on the basis of sample data . example: if we want to interpret the average income of employees for upcoming year so we have to interpret the income of employees on the basis of previous year's income of those employees
Saeed
thank you saeed, Akash. I understood.
Bhavani
Finding correlation and regression
explain statistics whether it is a science or arts or both
I would say art is a creation. A chef is an artist. They create new dishes just like the painters. I believe one who creates something new, is an artist. So, Statistics is also an art, if you know it, you can create some new formula, theory, law, etcetera. It is also Science. So yes, it is both.
Rohan
how do you use the normal distribution table when testing the hypothesis
Davia
Rohan
percentages of all the possible outcomes are measured. This is so simple and bases on the questionnaire or interview schedule. It's just measuring the probability chances of high %age of the either part of the hypothesis ... dependent ..independent. data is classified on the basis of respondents
saifuddin
what percent of the students would be expected to score above 95?
inferential statistics is what?
in which we make infrences (hypothsis)
surpose a data set of 2,3,5,6,1,4 are given find median
lucy
Mean (average) 4... Median (middle term) 3.5.. Mode (frequency) every element in a set has 1 frequrncy
Akash
i arrange the data set in ascending order. that is, 1,2,3,4,5,6. then find the data set that falls in the middle. in this case, 3 & 4 fall in the middle. you then sum and obtain the average. that is, (3+4)/2=3.5. therefore, 3.5 is the median.
Gbenga
both of you are correct.
Joseph
hello guys
Abasikponke
thanks
lucy
great to be here
King
how does a line graph look
King
hi
Davia
hello
lucy
pls who knows how line graph look like
King
line graph usually have a straight line running through axis
Dike
am new here anyone willing to orient me?
Timothy
find the media of the following numbers 61,64,67,70,73
my body pls
lucy
67
Benmike
Benmike
what is the percentile for the set of data in the class C and frequency F(c,f)given by (9.3-9.7,2) (9.8-10.2,5) (10.3-10.7,12) (10.8-11.2,17) (11.3-11.7,14) (11.8-12.2,6) (12.3-12.7,3) (12.8-13.2,1)
how to find median
arrange ascending and desending order than the mid value is Median
rajendra
ok
Hrishe
what if it is a group data
Oloyede
mean/ medium/ mode
Michelle
n\2 and n+1\2
An operational manager at a manufacturing company is interested in the level of satisfaction of computer buyers. The manager has developed a satisfaction scale of 1-10 to mark their level of understanding with the company.What is the population of the interest?
Any clues
Virtual
how to use grouped and ungrouped data
Just a test from gplay
how come 5.67
by dividing 11.37 on 2
saifuddin
by dividing 11.34 on 2
saifuddin
what is index number?
vinayak
What is the differences between quota an lottery system of sampling
EGBE
What are the are the characteristics that are critically expedients in selecting the sample size
EGBE
fit a binomial distribution for the following data and test the goodness of fit x: 0 1 2 3 4 5 6 f: 5 18 28 12 7 6 4
solution
Mano
Mano
Simonsakala
It is a square chi
Nelson
But can't be a binomial because, the x numbers are 0 to 6, instead those would be "0" or "1" in a straight way
Nelson
You can do a chi-square test, but the assumption has to be a normal distribution, and the last f's number need to be "64"
Nelson
sorry the last f's numbers : "6 and 4" which are the observed values for 5 and 6 (expected values)
Nelson
hi
rajendra
can't understand basic of statistics ..
rajendra
Sorry I see my mistake, we have to calculate the expected values
Nelson
So we need this equation: P= (X=x)=(n to x) p^x(1-p)^n-x
Nelson
why it is not possible brother
ibrar
were n= 2 ( binomial) x= number of makes (0 to 6) and p= probability, could be 0.8.
Nelson
so after we calculate the expected values for each observed value (f) we do the chi-square. x^2=summatory(observed-expected)^2 / expected and compare with x^2 in table with 0.8
Nelson
tomorrow I'll post the answer, I'm so tired today, sorry for my mistake in the first messages.
Nelson
It is possible, sorry for my mistake
Nelson
two trader shared investment and buoght Cattle.Mr.Omer bought 255 cows & rented the farm for a period of 32 days. Mr. Ahmed grazed his Cattle for 25 days. Mr. Ahmed's cattle was 180 cows.Together they profited $7800. the rent of the farm is$ 3000 so divide the profit per gows/day for grazing day
Mohamed
how to start this book, who is reading thins first time
It is my first time reading this book
Good one
ihsan