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EPI LEC > Midterms Quiz Compilation > Flashcards

Midterms Quiz Compilation Flashcards

1
Q

The correlation between coefficient between X and –X

A

-1

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2
Q

What does significant result in a chi-square test imply?

A

It implies that the sample is not representative of
the population

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3
Q

How many cases need to appear in one category for chi-square?

A

5

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4
Q

What type of data do you need for a chi-square test?

A

CATEGORICAL

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5
Q

For the chi-square test to be effective the expected value for each cell in the contingency table has to at least

A

5

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6
Q

The null hypothesis in the chi-square test states that

A

THE ROWS AND COLUMNS IN THE TABLE
ARE ASSOCIATED

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7
Q

Which statement is not correct about the chi-square test statistic?

A

A VALUE CLOSE TO 0 WOULD INDICATE
EXPECTED COUNTS ARE MUCH
DDIFFERENT FROM OBSERVED COUNTS

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8
Q

A researcher asked 933 people what…..

A

CHI-SQUARE TEST

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9
Q

What must be true about the expected values in a chi-square test?

A

GREATER THAN OR EQUAL TO 5

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10
Q

Analysis of variance is a statistical method of comparing the —- of several populations

A

MEANS

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11
Q

When incidence rates are available, comparing rates using a ratio measure of association is best don’t with a odds ratio

A

FALSE

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12
Q

An odd ratio greater than 1 indicates a negative association between exposure and outcome

A

FALSE

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13
Q

The prevalence ration can be used in a case control study or any study where the outcome data is prevalence

A

FALSE

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14
Q

January 1, 2003. On June 5, 2003, it was discovered that 75 of those gym patrons currently had gym-related injuries. After June 5, the remaining injury-free patrons were enrolled in a cohort study, classified as machine-users (n=1000) and free-weight users (n=425), and followed for 3 years. 85 machine-users and 15 free-weight users became injured in the 3 years. All follow- up stopped on exactly June 5, 2006. Assuming complete ascertainment and no drop-outs: Calculate the odds ratio for injury among machine users

A

2.5

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15
Q

Fourteen of the volunteers who were given the new medicine have an upset stomach, and 42 of the volunteers who were given the new medicine do not have an upset stomach. In volunteers who did not take the medication, two people have an upset stomach and 83 do not have an upset stomach. Calculate the

relative risk of having an upset stomach (event) after taking the new medicine (exposure)

A

10.4

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16
Q

Fourteen of the volunteers who were given the new medicine have an upset stomach, and 42 of the volunteers who were given the new medicine do not have an upset stomach. In volunteers who did not take the medication, two people have an upset stomach and 83 do not have an upset stomach. What is the Probability in non exposure group?

A

0.024

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17
Q

The first way that the odds ratio can be calculated is by comparing those with the outcome to those without the outcome

A

TRUE

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18
Q

Relative Risk is often used when the study involves comparing the likelihood, or chance, of an event occurring between two groups. Relative Risk is considered a descriptive statistic and an inferential statistic; as it does not determine statistical significance.

A

1ST statement is true and 2ND is false

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19
Q

Relative Risk utilizes the probability of an event occurring in one group compared to the probability of an event occurring in the other group. It requires the examination of two dichotomous variables, where one variable measures the event (occurred vs. not occurred) and the other variable measures the groups (group 1 vs. group 2)

A

BOTH STATEMENT ARE TRUE

20
Q

A way to present disease occurrence using a denominator hat is comprised of person time and has some advantages over using rates

A

INCIDENCE RATIO

21
Q

Fourteen of the volunteers who were given the new medicine have an upset stomach, and 42 of the volunteers who were given the new medicine do not have an upset stomach. In volunteers who did not take the medication, two people have an upset stomach and 83 do not have an upset stomach. What is the Probability in exposure group?

A

0.25

22
Q

A way to present disease occurrence using a denominator hat is comprised of person time and has some advantages over using rates

A

INSIDENCE DENSITY RATIO

23
Q

To use ANOVA you should have more than 3 observations

A

TRUE

24
Q

ANOVA helps to answer a hypothesis by splitting up the sources of variability

A

TRU

25
Q

Analysis of variance is a statistical method of comparing the — of several populations

A

MEANS

26
Q

The —- sum of squares measure the variability of the observed values around their respective treatment means

A

ERROR

27
Q

A one way ANOVA will tell you that at least two groups were different from each other but it won’t tell you which groups were different

A

TRUE

28
Q

ANOVA provides a statistical test for determining whether there is enough evidences to accept the null hypothesis that all man equal

A

FALSE

29
Q

To determine whether the test statistic of ANOVA is statistically significant. It can be compared to a critical value. What two pieces of information are needed to determine the critical valued.

A

SAMPLE SIZE, NUMBER OF GROUPS

30
Q

It is the needed to determine the computed F value

A

MSTr

31
Q

the —- sum of squares measures the variability of the sample treatment means around the overall means

A

TREATMENT

32
Q

What is needed to solve for trtdf?

A

k

33
Q

The pearson correlation technique works best with the linear relationships.

A

TRUE

34
Q

Correlational analysis is unable to tell how much one variable will change if another variable changes a certain

A

TRUE

35
Q

A non-directional hypothesis predicts a negative correlation between two variables

A

FALSE

36
Q

R and rs are symbols representing two different types of correlation coefficient

A

TRUE

37
Q

The correlation coefficient between X and –X is

A

-1

38
Q

If X is measured in your and X is measured in minutes, then correlation coefficient has the unit.

A

NO UNIT

39
Q

A positive and a negative relationship may have the same strength

A

TRUE

40
Q

In scatter diagram, if most of the points lie in the first and third quadrants, the coefficient of correlation is

A

Positive

41
Q

The value of the coefficient of the correlation r lies between

A

-1 and 1

42
Q

If the points on the scatter diagram show no tendency either to increase together or decrease togher the value of r will be close to

A

0

43
Q

If the points on the scatter diagram indicate that as one variable increases the other variable tends to decrease the value of r will be

A

NEGATIVE

44
Q

The correlation coefficient is the —- of the two regression coefficients

A

GEOMETRIC MEAN

45
Q

When the ratio of variations in the related variables is constant, it is called

A

LINEAR CORRELATION

46
Q

If both variable X and Y increase or decrease stimultaneously, then the coefficient of the correlation will be

A

POSITIVE

47
Q

If one item is fixed and unchangeable and the other term varies, the correlation coefficient will be

A

ZERO

EPI LEC (2 decks)

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