According to a census company, 7.1% of all babies born are of low birth weight. An obstetrician wanted to know whether mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies. She randomly selected 240 births for which the mother was 35 to 39 years old and found 26 low-birth-weight babies. Complete parts (a) through (c) below. Ho: V0.071 H,: V0.071 Use technology to compute the P-value for this test. Use the Tech Help button for further assistance. P-value = (Round to three decimal places as needed.) State a conclusion for this test in the context of the obstetrician's question. Choose the correct answer below. O A. Do not reject the null hypothesis. There is sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level of significance. O B. Reject the null hypothesis. There is sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level significance. OC. Do not reject the null hypothesis. There is not sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level of significance. O D. Reject the null hypothesis. There is not sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level of significance. (c) Answer the obstetrician's question at the a = 0.05 level of significance using a z-test for a population proportion. State the null and alternative hypotheses for this test. Họ: 0.071 H4: 0.071 Use technology to compute the P-value for this test. Use the Tech Help button for further assistance. P-value = (Round to three decimal places as needed.) State a conclusion for this test in the context of the obstetrician's question. Choose the correct answer below. O A. Reject the null hypothesis. There is sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level of significance. O B. Reject the null hypothesis. There is not sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level of significance. OC. Do not reject the null hypothesis. There is not sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level of significance. O D. Do not reject the null hypothesis. There is sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies at the a = 0.05 level of significance.

In 1997, in terms of population, county A ranked 9th out of 76 counties. What was its percentile rank? (Round your answer to the nearest whole number.) th percentile

Because colas tend to replace healthier beverages and colas contain caffeine and phosphoric acid, researchers wanted to know whether cola consumption is associated with lower bone mineral density in women. The accompanying data lists the typical number of cans of cola consumed in a week and the femoral neck bone mineral density for a sample of 15 women. Complete parts (a) through (f) below. Click the icon to view the women's data. (a) Find the least-squares regression line treating cola consumption per week as the explanatory variable. y=x+( (Round to four decimal places as needed.) Colas per Week and Bone Density colas per week 0 1 1 1 2 2 2 3 5 5 5 6 7 7 7 Print Bone Mineral Density (g/cm³) D 0.906 0.867 0.879 0.869 0.851 0.833 0.834 0.813 0.757 0.761 0.758 0.728 0.698 0.707 0.704 Done - X ●●●

What proportion of the general population has an IQ of 70 or less?

In the same group of 20 students, GPA was measured before the semester and after the semester. What test would be used to test for differences in GPA across these two time-points?

A certain county had a population of 34,485 people. The county hospital is interested in estimating the number of people in the county with blood type-O. To do this, they test blood samples from 228 patients. Out of this group, 10 have blood type-O. Use this sample to estimate the number of people in the county with blood type-O.

A music fan claims that R&B songs and Rap songs differ in terms of their positivity.  The individual collected two independent random samples from the population of all songs on Spotify.  Fifteen R&B songs and another fifteen Rap songs were collected and their Valence was recorded.  Remember, the variable Valence is measured on a 0 to 1 scale.  Songs with high valence sound more positive (e.g. happy, cheerful, euphoric), while songs with low valence sound more negative (e.g. sad, depressed, angry). We will subtract (R&B – Rap) and use the 10% significance level.  Assume the Central Limit Theorem conditions hold.  The data set is called RBRapSample31.  Please import the data set into Rguroo or find it in our group.   Define the population parameter in context and symbols in one sentence.   State the hypotheses you would use to test the claim that a difference exists in the mean Valence between R&B and Rap songs using correct notation.

The American Heart Association is about to conduct an anti-smoking campaign and wants to know the fraction of Americans over 33 who smoke. step 1 of 2: suppose a sample of 1267 Americans over 33 is drawn. Of these people, 913 don't smoke. Using the data, estimate the proportion of Americans over 33 who smoke. Enter your answer as a decimal number rounded to three decimal places.

The indicated IQ score, x, is

Suppose the prevalence of "dance fever" at a college is 40% among women and 10% among men. If there are half as many men as women, what is the overall prevalence of dance fever at the college? What proportion of people without dance fever at that college are women?