Download CNSL 503 Module 7 Correlational Analysis and Linear Regression Exam with verified solution and more Exams Statistics in PDF only on Docsity!
CNSL | 503 | Module | 7 | Correlational |
Analysis | and | Linear | Regression | Exam | with
| verified | solutions
___ | is | performed | to | measure | and | describe | how | two | quantitative | variables | are | related | - | Correct | answer | ✔Correlational | analysis Correlational | analysis | is | performed | when | variables | are | observed | in | their | ___ | rather | than | being | manipulated | in | a | study | - | Correct | answer | ✔observed | in | their | natural | state ___ | describes | the | direction | of | a | relationship, | form | of | a | relationship | (linear, | curvilinear, | quadratic, | or | cubic), | and | the | degree | of | a | relationship. | - | Correct | answer | ✔Correlation ___ | describes | the | direction | of | the | linear | relationship | between | two | variables | - | Correct | answer | ✔Covariance If | two | variables | covary, | one | of | two | directions | exist | in | the | plot | of | variables:
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- | - | Correct | answer | ✔1. | Both | variables | increase | or | decrease | together. | OR
- | As | one | variable | increases | the | other | decreases
Covariance | does | not | imply | __ | - | Correct | answer | ✔Covariance | does | not | imply | causation ___ | is | a | limitation | of | correlational | studies, | however, | correlation | being | established | is | the | first | step | in | determining | ___ | - | Correct | answer | ✔Causation, | causality The | most | common | ways | correlations | are | represented | graphically | are | with | ___, | a | graph | in | which | two | measurements | are | obtained | from | each | individual | in | the | study | and | paired | variable | scores | are | plotted | as | coordinate | pairs. | - | Correct | answer | ✔scatterplots In | scatterplots, | the | independent | variable | is | on | the | ___ | and | the | dependent | variable | is | on | the | __ | - | Correct | answer | ✔In | scatterplots, | the | independent | variable | is | on | the | x-axis | and | the | dependent | variable | is | on | the | y-axis. In | scatterplots, | the | independent | variable | is | called | the | ___ | and | the | dependent | variable | is | called | the | __ | - | Correct | answer | ✔explanatory, | response A | linear | relationship | describes | when | plotted | pairs | ___ | - | Correct | answer | ✔approximate | a | straight | line A | positive | correlation | indicates | - | Correct | answer | ✔that | both | variables | are | increasing | together
r | =0.7 | to | 0.9 | indicates | a | - | Correct | answer | ✔high | correlation r= | 0.5 | to | 0.7 | indicates | - | Correct | answer | ✔moderate | correlation r=0.3 | to | 0.5 | indicates | - | Correct | answer | ✔low | positive | correlation r=0.0 | to | 0.3 | indicates | - | Correct | answer | ✔very | weak | or | negligible | correlation As | the | r-values | move | closer | to | +1 | and | -1, | the | points | resemble | ___ | - | Correct | answer | ✔straight | lines ___ | results | in | smaller | correlation | coefficients | and | inaccurate | relationship | measures | between | two | variables | - | Correct | answer | ✔Range | restriction True/False: Correlational | analysis | is | not | impacted | by | outliers | - | Correct | answer | ✔False, | correlational | analysis | is | impacted | by | outliers ___ | is | a | correlation | coefficient | that | is | calculated | to | determine | the | degree | and | direction | of | the | relationship | between | X | and | Y | if | a | linear | relationship | exists. | - | Correct | answer | ✔Pearson's | r Pearson's | r | is | a | sample | statistic, | whereas | __ | is | the | population | parameter | - | Correct | answer | ✔ρ | "rho"
Pearson's | r | is | defined | by | what | ratio? | - | Correct | answer | ✔r | = | degree | to | which | X | and | Y | vary | together | (covariability) | / | degree | to | which | X | and | Y | vary | separately | (separate | variability) ___ | involves | making | specific | assumptions | about | populations | and | are | used | when | a | population | has | a | normal | distribution, | samples | have | equal | variances, | a | linear | relationship, | and | independent | variables. | Examples: | ANOVA, | t-tests, | z-tests, | Pearson's | r | - | Correct | answer | ✔Parametric | tests __ | involves | making | no | assumptions | about | the | population | parameters | when | data | are | not | normal | and | a | correlation | needs | to | be | determined | - | Correct | answer | ✔Nonparametric | test | aka | distribution-free | tests ____ | is | a | nonparametric | test | used | to | determine | correlations, | used | for | ordinal | data | or | for | non-normal | continuous | data, | ie | data | converted | to | ranks, | sometimes | used | with | normal | data | as | it | is | not | sensitive | to | outliers | - | Correct | answer | ✔Spearman's | ρ Outliers | in | correlation | coefficients | can | cause | - | Correct | answer | ✔inaccurate | conclusions | to | be | drawn | from | researchers | due | to | skewed | results True/false Outliers | can | be | a | result | of | true | values | - | Correct | answer | ✔True
The | best | fit | regression | line | always | passes | through | what | pair | of | coordiantes? | - | Correct | answer | ✔(x̄ ,ȳ) | The | mean | for | x, | The | mean | for | y True/false Linear | regression | creates | a | prediction, | it | does | not | guarantee | exact | values | - | Correct | answer | ✔True What | is | the | regression | equation? | - | Correct | answer | ✔y=bx+a b=slope a=y-intercept (x, | y) | = | pair | of | coordinates In | model | coefficient | statistical | software | output | tables, | where | do | you | identify | the | slope | and | y-intercept? | Where | do | you | ID | the | statistical | significance? | - | Correct | answer | ✔Under | estimate, | the | first | value | is | y-intecept, | the | second | value | is | the | slope. | y=slopex+y-intercept Statistical | significance | is | the | bottom | row | P | value In | a | Model | Fit | Measures | model | test, | how | do | you | identify | the | regression | equation | and | statistical | significance? | - | Correct | answer | ✔Calculated | F | ratio | listed | under | F. | determine | if | this | exceeds | the | Fcrit | use | df1, | df2. | F(df1, | df2) | = | Fcalc, | p-value
How | do | you | report | a | regression | equation | in | APA | format? | - | Correct | answer | ✔The | equation | Y=slopex+y-intercept | is/is | not | statistically | significant | in | predicting | Y | from | X. | F(df1, | df2) | = | Fcalc, | p-value Example: | The | equation | Y=32x+1 | is | statistically | significant | in | predicting | cost | of | a | diamond | from | weight | in | carats. | F(1,21)=32, | p<0. __ | is | the | amount | of | variation | of | y | values | that | can | be | explained | by | changes | in | the | x | values. | (the | degree | to | which | the | variance | of | a | variable | is | expressed | by | the | best | fit | line_ | - | Correct | answer | ✔Proportion | of | variance | accounted | for The | coefficient | of | determination | is | represented | by | - | Correct | answer | ✔r² The | r² | ratio | compares | - | Correct | answer | ✔variance | explained | by | the | model/total | variance, | an | effect | size A | larger | r² | indicates | - | Correct | answer | ✔smaller | error, | more | precise | predictions A | smaller | r² | indicates | - | Correct | answer | ✔larger | error, | less | precise | predictions an | r² | value | of | 0.17 | indicates | - | Correct | answer | ✔17% | of | variability | in | Y | can | be | predicted | from | X
can | be | predicted | from | the | given | X. | This | means | that | about | 80% | of | the | Y | values | are | attributed | to | other | variables. | The | equation | is | not | statistically | significant | in | predicting | Y, | F | (1,13) | = | 3.31, | p | = | 0.
