Question

**6.34 Prenatal vitamins and Autism:** Researchers
studying the link between prenatal vitamin use and autism surveyed
the mothers of a random sample of children aged 24 - 60 months with
autism and conducted another separate random sample for children
with typical development. The table below shows the number of
mothers in each group who did and did not use prenatal vitamins
during the three months before pregnancy (periconceptional period).
(Schmidt, 2011)

Autism | Typical Development | Total | |
---|---|---|---|

No vitamin | 111 | 70 | 181 |

Vitamin | 143 | 159 | 302 |

Total | 254 | 229 | 483 |

(a) State appropriate hypotheses to test for independence of use of prenatal vitamins during the three months before pregnancy and autism.

Ho: p_{vitamin} = p_{no vitamin}

Ha: p_{vitamin} < p_{no vitamin}

Ho: p_{vitamin} = p_{no vitamin}

Ha: p_{vitamin} ? p_{no vitamin}

Ho: p_{vitamin} = p_{no vitamin}

Ha: p_{vitamin} > p_{no vitamin}

(b) Complete the hypothesis test and state an appropriate
conclusion.

What is the value of the test statistic for this test? *(Please
round to two decimal places)* What is the p-value associated
with this test? *(Please round to four decimal places)* The
result of the hypothesis is:

Since p<? we fail to reject the null hypothesis

Since p ? ? we do not have enough evidence to reject the null hypothesis

Since p ? ? we reject the null hypothesis and accept the alternative

Since p ? ? we accept the null hypothesis

Since p<? we reject the null hypothesis and accept the alternative

Answer #1

a)Null Hypothesis Ho: pvitamin = pno vitamin

Alternative Hypothesis Ha: pvitamin ? pno vitamin

b) Under H0, the expected frequencies are

Obs. Freq | Exp. Freq | |||||

Autism | Typical Dev | Total | Autism | Typical Dev | Total | |

No Vitamin | 113 | 70 | 181 | 95.18 | 85.82 | 181.00 |

Vitamin | 143 | 159 | 302 | 158.82 | 143.18 | 302.00 |

Total | 254 | 229 | 483 | 254 | 229 | 483.00 |

The calculation for test statistic is

Obs. Freq( O ) | Exp. Freq ( E ) | (O-E)^2/E | |

111 | 95.18 | 2.629 | |

70 | 85.82 | 2.916 | |

143 | 158.82 | 1.576 | |

159 | 143.18 | 1.748 | |

Total | 483 | 483 | 8.869 |

The test statistic is

Degrees of freedom = (2-1)*(2-1) = 1

The critical value of Chi square for 1 df at 5% significance level is 3.841

The P-Value is 0.0029

**Since p<? we reject the null hypothesis and accept
the alternative**

Prenatal vitamins and Autism. Researchers
studying the link between prenatal vitamin use and autism surveyed
the mothers of a random sample of children aged 24 - 60 months with
autism and conducted another separate random sample for children
with typical development. The table below shows the number of
mothers in each group who did and did not use prenatal vitamins
during the three months before pregnancy.
Prenatal Vitamin
Autism
Typical Development
Total
No vitamin
112
66
178
Vitamin
143
161...

Prenatal
vitamins and Autism. Researchers studying the link between
prenatal vitamin use and autism surveyed the mothers of a random
sample of children aged 24 - 60 months with autism and conducted
another separate random sample for children with typical
development. The table below shows the number of mothers in each
group who did and did not use prenatal vitamins during the three
months before pregnancy.
Prenatal Vitamin
Autism
Typical Development
Total
No vitamin
108
64
172
Vitamin
138
155...

Prenatal vitamins and Autism. Researchers
studying the link between prenatal vitamin use and autism surveyed
the mothers of a random sample of children aged 24 - 60 months with
autism and conducted another separate random sample for children
with typical development. The table below shows the number of
mothers in each group who did and did not use prenatal vitamins
during the three months before pregnancy.
Prenatal Vitamin
Autism
Typical Development
Total
No vitamin
116
67
183
Vitamin
146
165...

Prenatal vitamins and Autism. Researchers
studying the link between prenatal vitamin use and autism surveyed
the mothers of a random sample of children aged 24 - 60 months with
autism and conducted another separate random sample for children
with typical development. The table below shows the number of
mothers in each group who did and did not use prenatal vitamins
during the three months before pregnancy.
Prenatal Vitamin
Autism
Typical Development
Total
No vitamin
109
63
172
Vitamin
138
156...

Prenatal vitamins and Autism. Researchers
studying the link between prenatal vitamin use and autism surveyed
the mothers of a random sample of children aged 24 - 60 months with
autism and conducted another separate random sample for children
with typical development. The table below shows the number of
mothers in each group who did and did not use prenatal vitamins
during the three months before pregnancy.
Prenatal Vitamin
Autism
Typical Development
Total
No vitamin
110
65
175
Vitamin
141
158...

Prenatal
vitamins and Autism. Researchers studying the link between
prenatal vitamin use and autism surveyed the mothers of a random
sample of children aged 24 - 60 months with autism and conducted
another separate random sample for children with typical
development. The table below shows the number of mothers in each
group who did and did not use prenatal vitamins during the three
months before pregnancy.
Prenatal Vitamin
Autism
Typical Development
Total
No vitamin
112
66
178
Vitamin
143
161...

It is believed that nearsightedness affects about 8% of all
children. In a random sample of 194 children, 21 are
nearsighted.
(a) Construct hypotheses appropriate for the following question: do
these data provide evidence that the 8% value is inaccurate?
Ho: p = .08
Ha: p ≠ .08
Ho: p = .08
Ha: p > .08
Ho: p = .08
Ha: p < .08
(b) What proportion of children in this sample are
nearsighted?
(round to four decimal places)
(c)...

A USA Today/Gallup poll conducted between 2010 and 2011 asked a
group of unemployed and underemployed Americans if they have had
major problems in their relationships with their spouse or another
close family member as a result of not having a job (if unemployed)
or not having a full-time job (if underemployed). 27% of the 1,145
unemployed respondents and 25% of the 675 underemployed respondents
said they had major problems in relationships as a result of their
employment status.
(a)...

The China Health and Nutrition Survey aims to examine the
effects of the health, nutrition, and family planning policies and
programs implemented by national and local governments. It, for
example, collects information on number of hours Chinese parents
spend taking care of their children under age 6. The side-by-side
box plots below show the distribution of this variable by
educational attainment of the parent. Also provided below is the
ANOVA output for comparing average hours across educational
attainment categories.
Df...

6.16 Is college worth it? Part I: Among a
simple random sample of 331 American adults who do not have a
four-year college degree and are not currently enrolled in school,
48% said they decided not to go to college because they could not
afford school.
(a) A newspaper article states that only a minority of the
Americans who decide not to go to college do so because they cannot
afford it and uses the point estimate from this survey...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 5 minutes ago

asked 24 minutes ago

asked 31 minutes ago

asked 46 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago