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Stats quiz
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Preguntas del test (100)
1The standard deviation is a better measure of spread than the range.
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2in a sample size of 11, the median is the 6th value.
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3which of the following are measures of location?
- Arange
- Bmean
- Cmode
- Dstandard deviation
- Econfidence intervals
4The five number summary comprises the mean, upper quartile, lower quartile, minimum and maximum.
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5Which of the following is not an example of descriptive statistics?
- Amean
- Bmedian
- Cstandard error
- Dstandard deviation
6the mean and standard deviation are always good measures of location and spread.
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7Which of the following are measures of spread?
- AStandard error
- BStandard deviation
- Crange
- Dmedian
- EInter quartile range
- Fmean
8Box and whisker plots display...
- Amedian
- Bupper quartile
- Cinter-quartile range
- Dmean
9Histograms display all the data in a sample.
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10A box and whisker plot denotes outliers as asterisks.
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11The standard deviation is a descriptive statistics tool that varies with sample size.
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12Increasing the number of bins in a histogram always results in smooth data.
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13Populations can be defined using which unknown parameters?
- Aμ
- Bπ
- Cσ
- Dρ
14The population mean is a measure of spread.
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15We can estimate μ using the sample standard deviation, s.
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16Normal distribution is positively skewed.
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17Which of the following statements is true concerning a normal distribution?
- AIt is non-symmetrical
- BIt has no skew
- Cit describes data that varies on a continuous scale
- Dit is an S shaped curve
18The mean and standard deviation both need units.
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19In a normal population, the median is roughly equal to μ
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20Non-symmetrical data is always skewed.
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21Which of the following tend to be more appropriate measures when data is skewed.
- Amean
- Bmedian
- Crange
- Dstandard deviation
- Einter-quartile range
22Statistical tests tend to be robust so data having a normal distribution is not always that important.
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23Which of the following is not a legitimate method of assessing normality?
- Ahistogram
- Bnormal probability plot
- Cbox and whisker plot
24The area under the normal distribution curve is equal to 1.
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25Which of the following statements is true regarding a normal population
- Athe upper quartile is μ + 0.0675 σ
- B95% of the population lie within 1 standard error of the mean
- Cthe lower quartile is μ - 0.675 σ
- Dthe mean is bigger than the standard deviation
26In a normal population of men, 30% are said to weigh more than 180 lbs, 20% are said to weigh less than 110 lbs and 95% more than 90 lbs.
Which of the following statements is true?- A0.7 men weigh less than 180 lbs
- B80% of men weigh more than 110 lbs
- C0.5 weigh less than 90 lbs
- D50% weigh between 110 and 180 lbs.
27confounded groups are said to be comparable.
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28X = μ + Zσ
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29Which of the following statements is correct?
- AP is the inverse cumulative probability at X
- BX is the cumulative probability at P
- CP is the cumulative probability at X
30A Z score expresses a multiple of standard deviations away from the population mean.
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31Which of the following statements is correct regarding a normal distribution?
- A68% of the population lies between μ +/- SE
- B95% of the population lies between μ +/- 2SE
- C97% of the population lies between μ +/- 3SE
32Sample means from larger sample sizes are better estimates of μ.
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33The standard deviation is a special form of standard error that takes into account the sample size.
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34X is the inverse cumulative probability at P
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35Which of the following is true regarding standard error?
- AIt does not take into account sample size.
- BIt is a descriptive statistics tool.
- CIt is used as an estimate of how far a sample mean is from the population mean.
36A hypothesis test assumes that the null hypothesis is true.
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37The T-test is a type of hypothesis test.
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38The T-test uses the sample means and standard error to calculate a T-test statistic.
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39A P-value >0.05 is significant.
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40Which of the following is true regarding a type II error?
- AIt is associated with P-values.
- BIt is associated with sample size.
- CIt is the probability of wrongly accepting the null hypothesis.
- DThey are associated with regression analyses.
41A type 1 error is wrongly rejecting the null hypothesis when it is in fact true.
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42A type 1 error can be described as a false positive.
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43Which of the following T-test statistics will give a significant P-value?
- A2.6
- B-4
- C0.9
- D-1.8
- E-2.1
44A P-value of 0.001 suggests strong significance.
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45there is a 99% chance that the T-test statistic will lie between -2 and +2 if the null hypothesis is true.
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46The paired T-test can also be known as...
- AOne-sample
- BTwo-sample
- CDependent
- DIndependent
47Which of the following is assumed for a paired T-test?
- ANormality of the residuals
- BNormality of the differences
- Cequal variance of both populations
- Dequal variance of the residuals
48The paired T-test tests for a relationship between 2 related samples.
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49The standard error is calculated differently for the paired T-test than it is in the unpaired T-test to reflect the different data structures.
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50The line of best fit uses the method of most squares.
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51A regression analysis assumes that y varies linearly with x.
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52Which of the following is an example of continuous data.
- ABlood type
- BHeight
- CTumour stage
- DWeight
- ELength
53Which of the following are parameters associated with a regression analysis.
- Aα
- Bμ
- Cβ
- Dχ
- Eσ
54α is estimated by a.
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55The regression line is μ(x) = α + βx
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56In a regression analysis, a T-value within +2 and -2 indicates a significant result.
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57In a regression analysis, the dependent variable is plotted on the y axis.
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58Which of the following assumptions is correct regarding a regression analysis.
- AThat the variation around the mean has a constant σ.
- BThat y is linearly related to x.
- CThat the variation about the line does not follow a normal distribution.
- DThat the residuals have an unequal variance.
59β is the population slope.
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60A regression analysis assumes β = 0
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61y is FEV1 in % and x is height in cm:
Y = -9.4 + 0.6x
Which of the following statements is true.- AFor every cm increase in height, there is a 0.6% increase in FEV1.
- BFor every 10 cm increase in height there is a 6% increase in FEV1.
- CWhen height is 130 cm, FEV1 is 68.6%.
- DWhen height is 0, FEV1 is 9.4.
62We can use the regression line to make predictions for values outside of our sample range.
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63A regression analysis quantifies the relationship between x and y.
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64An r value of 0 means there is no relationship between two variables.
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65Which of the following r values indicates a strong positive correlation
- A-0.9
- B0
- C-0.5
- D0.3
- E0.7
66if r = 0, then all of the variation in y is explained by x.
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67The most commonly used correlation coefficient is Fisher's exact test.
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68A correlation is a relationship between two continuous variable whether causal or not.
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69To find confidence intervals for correlation, only one variable needs to be normally distributed.
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70Which of the following statements is incorrect regarding binary variables.
- AThey follow a continuous scale
- Bthey are not normal
- Cthey are categorical variables
- Dthey can be recorded into several categories
71A population of binary variables can be described as 1's and 0's
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72Tumour stages are an example of ordinal categorical variable.
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73r/n is used to estimate μ
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74π can be described as the mean of 1's and 0's.
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75π is an analogue of the T-test.
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76Which of the following is true regarding a χ2 test?
- AElements in the table must be counts not proportions
- Bcounts must be independent
- Cobserved values must not be too small
- Dexpected values must not be too small
77A fisher's exact test is used if expected values are <5.
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78Non-independent counts in a χ2 test results in an increased χ2 statistic and smaller P-value
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79The principles of a χ2 test can be extended to other categorical variables.
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80A large χ2 test statistic is associated with a significant result.
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81Which of the following are ways to calculate the difference between π1 and π2?
- AD
- BOR
- CR
- DS
- EM
82If probability is P, then odds are calculated as P/1-P
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83Calculating confidence intervals for the odds ratio relies on the use of natural logarithms because the OR is symmetrical.
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84The SE is calculated the same for D, R and OR.
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85Which of the following statements is true regarding replication?
- AReplication removes bias from comparisons and gives validity.
- BReplication is the probability of detecting a difference.
- CReplication removes background variation.
- DReplication reduces the variance of estimators.
86Power is the probability of detecting a relationship
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87Power is a number.
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88Which of the following would increase power?
- AIncreasing sample size
- Ba larger difference between μ1 and μ2
- Csmaller standard deviation
- Dlarger standard deviation
- Ea greater level of significance
89Randomisation always removes bias.
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90Which of the following is an example of restricted randomisation?
- AStratification
- Bpseudo-replication
- Cfactorial design
- Dpower
91combining factors means we can reduce the number of replicates but still have the same power.
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92Psuedo-replication results in a misleadingly large P-value.
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93We can use factorial design to combine experiments and observe individual effects but not interactions.
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94All other things the same, a sample size of 500 will result in less power than a sample size of 50.
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95Blocking is an example of factorial design.
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96Restricted randomisation prevents confounding groups.
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97A non-significant result means the null hypothesis is true.
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98increasing sample size increases the power of detecting a difference.
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99No amount of replication will reduce existing bias if two groups are confounded.
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100Which of the following are associated with increasing sample size?
- Aincreasing standard deviation
- Bincreasing standard error
- Cincreasing power
- Ddecreasing standard deviation
- Edecreasing standard error
Información
- Descripción
- Test sobre Stats quiz, creado por lauren beck el 12/01/2020.
- Autor
- lauren beck
- Idioma
- English
- Visitas
- 2
- Valoración
- Aún sin valoraciones Valora este test