Bio 215 EXAM QUESTIONS WITH CORRECT ANSWERS.

Bio 215 EXAM QUESTIONS WITH
CORRECT ANSWERS
Which |of |the |following |test/s |require/s |independence |of |the |data |(more |than |one |can |be |
true)? |- |CORRECT |ANSWER✔✔-ANOVA |and |Chi-squared



When |should |you |use |the |Fisher's |exact |test |instead |of |the |Chi-square |test |for |a |2x3 |
Contingency |Table |(more |than |one |can |be |true)? |- |CORRECT |ANSWER✔✔-When |the |sample |
size |is |small |(e.g. |all |of |the |cell |counts |<5)



A |dentist |is |testing |if |gum |disease |can |be |prevented |by |using |mouthwash; |he |uses |a |Chisquare
|test |to |identify |if |there |is |an |association |between |using |mouthwash |(categorical |variable |with |


three |levels: |mouthwash |used |after |all |meals, |used |only |after |lunch, |not |used |at |all) |and |gum |
disease |(categorical |variable |with |two |levels: |gum |disease |present, |not |present). |What |is/are |
the |null |hypothesis/es |of |this |experiment |(more |than |one |can |be |true)? |- |CORRECT |
ANSWER✔✔-Gum |disease |is |not |associated |with |the |use |of |mouth |wash

Gum |disease |is |independent |from |the |use |of |mouth |wash

A |and |B



If |we |reject |the |null |hypothesis |from |Q.3, |which |is/are |true |(more |than |one |can |be |true)? |- |
CORRECT |ANSWER✔✔-A, |B, |and |C



Given |the |experiment |from |Q.3, |when |are |the |assumptions |of |the |Chi-square |test |met |(more |
than |one |can |be |true)? |- |CORRECT |ANSWER✔✔-When |each |individual |only |contributes |to |one
|cell |of |the |contingency |table



When |each |individual |is |exposed |to |only |one |of |the |mouthwash |treatments |(either |use |of |
mouth |wash |after |all |meals, |only |after |lunch, |or |not |used |at |all)

A |and |B

, Given |the |experiment |from |Q.3, |and |the |Chi-square |table |of |observed |values |below, |what |is |
the |Chi-square |(only |one |can |be |true)? |- |CORRECT |ANSWER✔✔-14.91



Given |the |experiment |from |Q.3, |and |the |Contingency |Table |from |Q.6, |what |are |the |degrees |of
|freedom |of |this |Chi-square |test |(only |one |can |be |true)? |- |CORRECT |ANSWER✔✔-2




Given |the |experiment |from |Q.3, |the |Contingency |Table |from |Q.6, |the |Chi-square |you |
calculated |in |Q.6, |the |degrees |of |freedom |you |estimated |in |Q.7, |and |the |table |of |the |critical |
values |of |the |Chi-square |distribution |on |the |right |which |is/are |true |(more |than |one |can |be |
true)? |- |CORRECT |ANSWER✔✔-The |critical |Chi-square |for |this |test |is |5.99 |(for |a |p=0.05) |and |
9.21 |(for |a |p=0.01)

The |calculated |Chi-square |is |> |than |the |critical |Chi-square |for |both |significance |levels |(p=0.01 |
or |p=0.05)

A |and |C



Given |the |results |of |the |Chi-square |test |in |Q.6-8, |which |is/are |true |(more |than |one |can |be |
true)? |- |CORRECT |ANSWER✔✔-You |have |enough |evidence |to |reject |the |null |hypothesis

Gum |disease |is |contingent |upon |the |use |of |mouthwash

A |and |B



Given |the |output |of |the |Chi-square |on |the |right, |which |is |testing |if |the |presence |of |bobcat |
(categorical |variable |with |two |levels: |Absent, |Present) |is |associated |with |Habitat |(categorical |
variable |with |three |levels: |Rural, |Suburban, |Urban), |which |is/are |true |(more |than |one |can |be |
true)? |- |CORRECT |ANSWER✔✔-The |habitat |type |is |associated |with |the |presence |or |absence |of
|bobcats



In |urban |habitats |there |are |less |bobcats |present |than |expected

A |and |B



Given |the |experiment |and |the |table |from |Q. |10, |which |is/are |true, |(more |than |one |can |be |
true)? |- |CORRECT |ANSWER✔✔-The |assumptions |of |the |Chi-square |are |met |(less |than |20% |of |
the |expected |frequencies |are |<5)