Question

In: Statistics and Probability

there is an old wives tale that women who eat chocolate during pregnancy are more likely...

there is an old wives tale that women who eat chocolate during pregnancy are more likely to have happy babies. a pregnancy magazine wants to test this claim, and it gathers 100 randomly selected pregnant women for its study. half of the women sampled agreed to eat chocolate at least once a day, while the other half agree to forego chocolate for the duration of their pregnancies. a year later, the ladies complete a survery regarding the overall happiness of their babies. the results are given in the following table. at the 0.01 level of significance, test the old wives' tale.

	happy babies	unhappy babies
with chocolate	24	26
without chocolate	22	28

state the null and alternative hypothesis

determine which distrubition to use for the test statistic, and state level of significance

gather date and calculate the necessary sample statistics

and draw a conclusion and interpret the decision

Solutions

Expert Solution

We have to perform chi square test for independence.

H₀ : The variables habit of having chocolate during pregnancy and nature of baby are independent.

H_a : The variables habit of having chocolate during pregnancy and nature of baby are dependent.

Observed frequency table :

We need to find expected frequency.

Expected frequency =

For example expected frequency for cell with chocolate and happy babies = ( 50* 46/100) = 23

Expected frequency table :

Now we need to find chi square statistic:

χ² = ; O is observed and E is expected.

χ² = 0.161

Critical value:

We are given level of significance α = 0.01

Degrees of freedom (df) = (r-1)(c-1) r is type of habits and c is number of types of nature of babies.

r = 2 and c = 2

df = (2-1)*(2-1) = 1

Therefore critical value χ²_(0.01,1) = 6.6349 -------- ( From chi square table )

Critical region : Reject H₀ if χ² is greater than χ²_(0.01,1) = 6.6349

fail to reject H₀ , if χ² is less than χ²_(0.01,1) = 6.6349

Decision : As χ² = 0.161 is less than χ²_(0.01,1) = 6.6349

We fail to reject H₀, so accept H₀

Conclusion: We do not have significant evidence that the variables habit of having chocolate during pregnancy and nature of baby are dependent ; that is they are independent.

So the women who eat chocolate during pregnancy are not more likely to have happy babies.

orchestra answered 1 year ago

Next > < Previous

Related Solutions

women who reported an earlier age at menarche were more likely to be heavier at age...

women who reported an earlier age at menarche were more likely to be heavier at age 7 years (average weight = 24.7 kg) compared with those who reported a later age at menarche (average weight = 23.2 kg) (P = 0.01). The correlation between weight at age 7 years and age at menarche was -0.17 (P = 0.009). Q: The -0.17 value is for what? how to find it and why it is important to mention?

The weight gain of women during pregnancy has an important effect on the birth weight of...

The weight gain of women during pregnancy has an important effect on the birth weight of their children. If the weight gain is not adequate, the infant is more likely to be small and will tend to be less healthy. In a study conducted in two countries, weight gains (in kilogram) of women during the third trimester of pregnancy were measured. The results are summarized in the following table. Country n ȳ s2 Egypt 6 3.8 5.76 Kenya 10 3.3...

For osteoporosis, since women are more likely to develop osteoporosis more than men. Why is this...

For osteoporosis, since women are more likely to develop osteoporosis more than men. Why is this the case? What are possible reasons that women are more likely to develop osteoporosis and what are the causes?

Currently, American women are dying from pregnancy-related complications more than women in other developed countries. Why...

Currently, American women are dying from pregnancy-related complications more than women in other developed countries. Why do you think that the maternal mortality rate is higher in the United States than in other nations? From a public health perspective, how can we improve?

Pregnant women were recruited during their first trimester to study the relationship between chocolate consumption during...

Pregnant women were recruited during their first trimester to study the relationship between chocolate consumption during pregnancy and risk of preeclampsia (pregnancy-induced hypertension). They were interviewed about chocolate consumption, age, race, education, smoking, body mass index, and previous pregnancy history. Participants were re-interviewed after delivery to obtain information on chocolate consumption during the third trimester of pregnancy. In addition, umbilical cord blood was collected at the time of delivery and measured for concentration of theobromine (the major metabolite of chocolate)....

why are men more likely to have colon cancer than women

When would estrogen and progesterone levels be very high in women? during pregnancy a few days...

When would estrogen and progesterone levels be very high in women? during pregnancy a few days after childbirth they will remain the same both during pregnancy and after childbirth

PREGNANCY 1. What is important to know about calorie recommendations for women who are pregnant? 2....

PREGNANCY 1. What is important to know about calorie recommendations for women who are pregnant? 2. What supplements are usually recommended for pregnant women and why? BREASTFEEDING 3. What are 2 benefits and 2 concerns related to breastfeeding? 4. How can you tell if the baby is receiving enough nourishment from breastfeeding (or from formula)? CHILDHOOD 5. What are 2 strategies to encourage healthy eating habits in children? 6. What is the division of responsibility (parents' job/child's job) when feeding...

It is believed that the women with some education beyond high school (H) are more likely...

It is believed that the women with some education beyond high school (H) are more likely to use contraceptives compared to women with an education level at or below a high school level (L). A study was conducted to test this claim and found out that 201 among 613 low-educated women (L) use contraceptives and 228 out of 848 women with some education beyond high school (H) use contraceptives. Does it appear that better-educated women are more likely to use...

Why are elderly women more likely to be in poverty then elderly men? After a lifetime...

Why are elderly women more likely to be in poverty then elderly men? After a lifetime of work and labor, why do some workers have inadequate pensions or no pension at all in their later years?

Subjects