Mathematics, 12.12.2019 06:31, greenhusky
The negative effects of ambient air pollution on children's lung function has been well established, but less research is available about the impact of indoor air pollution. the authors of an article investigated the relationship between indoor air-pollution metrics and lung function growth among children ages 6-13 years living in four chinese cities. for each subject in the study, the authors measured an important lung-capacity index known as fev1, the forced volume (in ml) of air that is exhaled in 1 second. higher fev1 values are associated with greater lung capacity. among the children in the study, 512 came from households that used coal for cooking or heating or both. their fev1 mean was 1423 with a standard deviation of 329. (a complex statistical procedure was used to show that burning coal had a clear negative effect on mean fev1 levels.)
a)calculate and interpret a 95% (two-sided) confidence interval for true average fev1 level in the population of all children from which the sample was selected. (round your answers to one decimal place.)
b)suppose the investigators had made a rough guess of 330 for the value of s before collecting data. what sample size would be necessary to obtain an interval width of 50 ml for a confidence level of 95%? (round your answer up to the nearest whole number.)
Answers: 1
Mathematics, 21.06.2019 13:20, animegirl02
What is the equation and solution for the sentence? the sum of a number and thirty-one is one hundred thirteen. write the equation as n-31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and add 31 to both sides. the answer is 144. write the equation as n-31=113 and add 31 to both sides. the answer is 144.
Answers: 1
Mathematics, 21.06.2019 23:30, meiyrarodriguez
Write an inequality for this sentence the quotient of a number and -5 increased by 4 is at most 8
Answers: 1
Mathematics, 22.06.2019 00:30, kitykay2399
An unknown number x is at most 10. which graph best represents all the values of x? number line graph with closed circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the left. number line graph with closed circle on 10 and shading to the left.
Answers: 1
The negative effects of ambient air pollution on children's lung function has been well established,...
Mathematics, 14.01.2020 19:31
Mathematics, 14.01.2020 19:31