# 0.2 Practice tests (1-4) and final exams  (Page 18/36)

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33 . The screening test has a 20 percent probability of a Type II error, meaning that 20 percent of the time, it will fail to detect TB when it is in fact present.

34 . Eighty percent of the time, the screening test will detect TB when it is actually present.

## 9.3: distribution needed for hypothesis testing

35 . The Student’s t -test.

36 . The normal distribution or z -test.

37 . The normal distribution with μ = p and σ = $\sqrt{\frac{pq}{n}}$

38 . t 24 . You use the t -distribution because you don’t know the population standard deviation, and the degrees of freedom are 24 because df = n – 1.

39 . $\overline{X}~N\left(0.95,\frac{0.051}{\sqrt{100}}\right)$
Because you know the population standard deviation, and have a large sample, you can use the normal distribution.

## 9.4: rare events, the sample, decision, and conclusion

40 . Fail to reject the null hypothesis, because α p

41 . Reject the null hypothesis, because α p .

42 . H 0 : μ ≥ 29.0”
H a : μ <29.0”

43 . t 19 . Because you do not know the population standard deviation, use the t -distribution. The degrees of freedom are 19, because df = n – 1.

44 . The test statistic is –4.4721 and the p -value is 0.00013 using the calculator function TTEST.

45 . With α = 0.05, reject the null hypothesis.

46 . With α = 0.05, the p -value is almost zero using the calculator function TTEST so reject the null hypothesis.

## 9.5: additional information and full hypothesis test examples

47 . The level of significance is five percent.

48 . two-tailed

49 . one-tailed

50 . H 0 : p = 0.8
H a : p ≠ 0.8

51 . You will use the normal test for a single population proportion because np and nq are both greater than five.

## 10.1: comparing two independent population means with unknown population standard deviations

52 . They are matched (paired), because you interviewed married couples.

53 . They are independent, because participants were assigned at random to the groups.

54 . They are matched (paired), because you collected data twice from each individual.

55 . $d=\frac{{\overline{x}}_{1}-{\overline{x}}_{2}}{{s}_{pooled}}=\frac{4.8-4.2}{1.6}=0.375$
This is a small effect size, because 0.375 falls between Cohen’s small (0.2) and medium (0.5) effect sizes.

56 . $d=\frac{{\overline{x}}_{1}-{\overline{x}}_{2}}{{s}_{pooled}}=\frac{5.2-4.2}{1.6}=0.625$
The effect size is 0.625. By Cohen’s standard, this is a medium effect size, because it falls between the medium (0.5) and large (0.8) effect sizes.

57 . p -value<0.01.

58 . You will only reject the null hypothesis if you get a value significantly below the hypothesized mean of 110.

## 10.2: comparing two independent population means with known population standard deviations

59 . ${\overline{X}}_{1}-{\overline{X}}_{2}$ , i.e., the mean difference in amount spent on textbooks for the two groups.

60 . H 0 : ${\overline{X}}_{1}-{\overline{X}}_{2}$ ≤ 0
H a : ${\overline{X}}_{1}-{\overline{X}}_{2}$ >0
This could also be written as:
H 0 : ${\overline{X}}_{1}\le {\overline{X}}_{2}$
H a : ${\overline{X}}_{1}>{\overline{X}}_{2}$

61 . Using the calculator function 2-SampTtest, reject the null hypothesis. At the 5% significance level, there is sufficient evidence to conclude that the science students spend more on textbooks than the humanities students.

62 . Using the calculator function 2-SampTtest, reject the null hypothesis. At the 1% significance level, there is sufficient evidence to conclude that the science students spend more on textbooks than the humanities students.

## 10.3: comparing two independent population proportions

63 . H 0 : p A = p B
H a : p A p B

quantitive discrete data
Raymond is a basketball player who takes four independent Free throws with 70% probability of getting a baskets on each shot. let X be the number of baskets Raymond gets. find the probability that she gets exactly two baskets
line y=a+bx for curve fitting is what?
y=a+bx is use to fit a straight line
Dillu
thx
Elrin
I didn't find ur question send again if I know I will answer
Dillu
where can i send it
Elrin
do u have an email
Elrin
send in this question box
Dillu
1. There is some evidence that REM sleep, associated with dreaming, may also play a role in learning and memory processing. For example, Smith and Lapp (1991) found increased REM activity for college students during exam periods. Suppose that REM activity for a sample of n=6 students during the
Elrin
nevermind
Elrin
sry I don't have clear answer fr this
Dillu
so, like you have bagA of 5red balls and 2 white balls and bagB of 4red balls and 6white balls,if a ball is picked up randomly from each bag, what's the probability that both will be different colors
what is questionnaire
list of simple and short questions asked to collect primary data
Atul
ok tnx
Akinwale
what is data science?
Aminu
data science is the study of data. It involves developing methods of recording, storing, and analyzing data to effectively extract useful information.
Akinwale
What is attribute?
Atul
what is mode?
Arnab
value with highest frequency in data set
Atul
what is data mining?
Aminu
Data mining is a process used by companies to turn raw data into useful information. By using software to look for patterns in large batches of data.
Akinwale
what is data analytics?
Aminu
a study of potential age discrimination considers promotion among middle managers in a large company...
how do we know to set null hypothesis
This is Statistic information
Thank average daily sales of a shopkeeper is Rs 200 with a standard deviation Rs 40 for how many days in a leap years his sales are exacted to be worth 1. less than Rs 150 and 2. over Rs 300 ?
what is the probability of at least one in "H"in three tosses of coin?
150%
Andrew
Sorry... 1-(.5^3)=7/8
Andrew
but how?
aneeza
1-(7/8)=1/8 total 8 out comes will appear in that "H" will appear in 7 times that's way
Dillu
sorry ... 1- (probability of getting no heads)=1-(1/8)=7/8
Dillu
HHH.HHT.HTH.THH.HHT.TTH.HTT=7 probability will 7/8
Atul
1-(3C0)(1/2)^3
Chitran
sorry probability has been my worst nightmare can you just break down the equation on how you solve it to give you 7/8
Vernissa
do you think that concurrent method of correlation describe any realtionship between supply and index in data given. supply 112,125,126,118,121,12 price 106,102,102,104,98
X 77 54 27 52 14 35 90 25 Y 35 38 60 40 35 56 34 50
Given the distribution X ~ U (2, 8)
minutes to drive from her suburban home to her midtown office.
Bilal
Define suitable populations from which the following samples are selected Persons in 200 homes are called by telephone in the city of Richmond & asked to name the candidate that they favor for election to the school board. On 5 different occasions it took a lawyer 21, 26, 24, 22 & 21 minutes to
Bilal
Define suitable populations from which the following samples are selected Persons in 200 homes are called by telephone in the city of Richmond & asked to name the candidate that they favor for election to the school board.
Bilal
first one is discrete population with more than two options so it should be multinomial population in second question variable is time so it's a continuous dist, and time is normally distributed so it is normal
fitting of regression equation
how to solve exercise to find difference between HoandHa
Give the info....
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