A researcher wants to know how long it takes, on average, for a certain species of bacteria to divide. She watches 22 cells through a microscope and times how long it takes them to divide. She obtains the following data, in hours: 7.4, 8.6, 6.6, 7.3, 9.1, 8.3, 8.9, 7.3, 9, 8.9, 8.4, 9.3, 7.4, 8.8, 8, 7.2, 10, 7.9, 7.4, 7.3, 7, 8.6 Assuming the population standard deviation is o = 1, construct a 90% confidence interval for the average time it takes this species of bacteria to divide. za = Margin of Error: E = We are 90% confident that this species of bacteria takes, on average, between hours and hours to divide. Submit Question ||

During a particularly dry growing season in a southern state, farmers noticed that there is a delicate balance between the number of seeds that are planted per square foot and the yield of the crop in pounds per square foot. The yields were the smallest when the number of seeds per square foot was either very small or very large. The data in the table show various numbers of seeds planted per square foot and yields (in pounds per square foot) for a sample of fields. A 2-column table with 15 rows. Column 1 is labeled number of seeds (per square foot) with entries 28, 75, 30, 43, 71, 35, 40, 59, 66, 79, 85, 81, 16, 33, 16. Column 2 is labeled yield (pounds per square foot) with entries 131, 171, 132, 166, 169, 150, 161, 183, 173, 161, 147, 157, 86, 145, 86. Which scatterplot represents the seed and yield data? A graph titled number of Seeds and Crop Yield has seeds (per square foot) on the x-axis, and yard (pounds per square foot) on the y-axis. The points curve up to a point, and…

A researcher was studying how much electricity (in kilowatt hours) people in Spain and Germany used in their homes last year. The researcher took a random sample of people from each country to test if the average electricity usage was significantly different. Here is a summary of their results: Electricity usage Country Mean StDev SE mean Spain 100 1780 415 41.5 Germany 100 1690 405 40.5 95% CI for us - PG: 90 + 114.4 The researcher wants to use these results to test Ho: µs = PG versus H: µs # pG. Assume that all conditions for inference have been met. Based on the interval, what do we know about the corresponding P-value and conclusion at the a = 0.05 level of significance? The P-value is less than a=0.05, and they should conclude that there is a difference between the means. The P-value is less than a=0.05, and they cannot conclude that there is a difference between the means. The P-value is greater than a=0.05, and they cannot conclude that there is a difference between the means.…

The scientific productivity of major world cities was the subject of a recent study. The study determined the number of scientific papers published between 1994 and 1997 by researchers from each of the 20 world cities, and is shown below.   City Number of papers City Number of papers City 1 15 City 11 30 City 2 22 City 12 55 City 3 20 City 13 25 City 4 20 City 14 55 City 5 23 City 15 10 City 6 21 City 16 15 City 7 99 City 17 77 City 8 24 City 18 22 City 9 24 City 19 22 City 10 33 City 20 29 Construct a 9090 % confidence interval for the average number of papers published in major world cities. _______<μ<________

CHAPTER 3. 1) A national health survey measured the serum HDL cholesterol levels in a large number of women. Following is a sample of 36 HDL levels (in milligrams per deciliter) that are based on the results of that survey. They have been sorted into numerical order. 25 26 26 26 27 28 33 34 36 37 37 38 41 41 42 43 44 44 44 44 45 45 45 46 46 47 50 51 56 58 64 66 68 69 80 85 (a) Find the first and third quartiles. (b) Find the median of these data. (c) Find the upper and lower outlier boundaries. (d) Are there any outliers? If so, list them. 1

A survey was conducted in 1990 asking American high school students to name their favorite subject in school. This survey found that, in 1990, the following proportions of students named each subject as their favorite: 30% History, 25% Math, 20% English, 15% Biology, 10% Chemistry. A researcher in the year 2020 conducts an identical survey, in order to see if students’ favorite subjects have shifted over the 30 years that have passed since the 1990 study was done. The researcher gives the survey to n=60 high school students, and gets the following observed frequencies and expected frequencies. FREQUENCY History Math English Biology Chemistry TOTAL fo 20 18 10 5 7 60 fe (.30)(60) = 18 (.25)(60) = 15 (.20)(60) = 12 (.15)(60) = 9 (.10)(60) = 6 60 QUESTION 1: Are the proportions on this problem from an assumption of all equal, or from past research?

Mr. Acosta, a sociologist, is doing a study to see if there is a relationship between the age of a young adult (18 to 35 years old) and the type of movie preferred. A random sample of 93 adults revealed the following data. Test whether age and type of movie preferred are independent at the 0.05 level.   Person's Age   Movie 18-23 yr 24-29 yr 30-35 yr Row Total Drama 8 16 10 34 Science Fiction 10 8 12 30 Comedy 11 8 10 29 Column Total 29 32 32 93   (a) What is the level of significance?State the null and alternate hypotheses. H0: Age and movie preference are not independent.H1: Age and movie preference are independent.H0: Age and movie preference are independent.H1: Age and movie preference are independent.    H0: Age and movie preference are not independent.H1: Age and movie preference are not independent.H0: Age and movie preference are independent.H1: Age and movie preference are not independent. (b) Find the value of the chi-square statistic for the sample. (Round…

The National Safety Board wants to determine the effect of seat belt use on saving lives. One study showed data on children under the age of 5 who were involved in car accidents in which at least one fatality occurred. Below is the table: X1 Survivors (0) Fatalities (1) Total No belt (0) Adult belt (1) Child seat (2) 1129 509 1638 X2 432 73 505 733 139 872 Total 2294 721 3015 Answer in 2 decimal places. a) Determine the probability that a child will be in a child seat. b) Determine the probability that X1 = 0 given X2 = 0 c) What is the probability of X1 = 1 given X2 = 0?

The scientific productivity of major world cities was the subject of a recent study. The study determined the number of scientific papers published between 1994 and 1997 by researchers from each of the 20 world cities, and is shown below. City Number of papers City Number of papers 18 City 11 City 12 City 1 19 City 2 17 21 City 3 18 City 13 23 City 14 City 15 City 4 25 City 5 21 29 21 City 16 City 17 City 6 26 City 7 17 27 City 8 20 City 18 19 City 19 City 20 City 9 15 25 City 10 30 8. Construct a 90 % confidence interval for the average number of papers published in major world cities. Use technology to help you with this problem (Minitab). If calculating by hand, do not round until the end, and keep at least 3 decimal places for your critical value. Give your answers to at least 2 decimal places. くルく

A Gallup Poll released in December 2010 asked 1019 adults living in the Continental U.S. about their belief in the origin of humans. These results, along with results from a more comprehensive poll from 2001 (that we will assume to be exactly accurate), are summarized in the table below. The survey takers were asked to select which of the 4 responses (column 1) were closest to their belief. Response Year: 2001 Year: 2010 Humans Evolved with God guiding (1) 37% 38% Humans evolved but God had no part 12% 16% in the process (2) God created humans in present form 45% 40% |(3) Other / No opinion (4) 6% 6% Select the appropriate hypotheses for the following research question: have beliefs on the origin of human life changed since 2001? o Ha: the population follows the 2001 distribution. o Ho: the population follows the 2010 distribution. o Ha: the population follows the 2010 distribution. o Ho: the population doesn't follow the 2010 distribution. o Ha: the population follows the 2001…