In the Focus Problem at the beginning of this chapter, a study was described comparing the hatch ratios of wood duck nesting boxes. Group I nesting boxes were well separated from each other and well hidden by available brush. There were a total of 483 eggs in group I boxes, of which a field count showed about 272 hatched. Group II nesting boxes were placed in highly visible locations and grouped closely together. There were a total of 815 eggs in group Il boxes, of which a field count showed about 274 hatched. LUSE SALT (a) Find a point estimate for p₁, the proportion of eggs that hatch in group I nest box placements. (Round your answer to four decimal places.) p Find a 95% confidence interval for pr. (Round your answers to three decimal places.) upper limit lower limit (b) Find a point estimate for p2, the proportion of eggs that hatch in group II nest box placements. (Round your answer to four decimal places.) p 2 Find a 95% confidence interval for pz. (Round your answers to three decimal places.) lower limit upper limit == Find a 95% confidence interval for p₁ - P₂. (Round your answers to three decimal places.) (c) lower limit upper limit Does the interval indicate that the proportion of eggs hatched from group I nest boxes is higher than, lower than, or equal to the proportion of eggs hatched from group II nest boxes?

A B C

Highway Signs. A driver’s ability to detect highway signs is an important consideration in highway safety. In his dissertation Highway Construction Safety and the Aging Driver (1994), Solomon Younes investigated the distance at which drivers can first detect highway caution signs. This distance is called the detection distance. An experiment was conducted to determine the effects that sign size and sign material have on detection distance. Four drivers were randomly selected for each combination of sign size (small, medium, and large), and sign material (1, 2, and 3). Each driver covered the same stretch of highway at a constant speed during the same time of day, and the detection distance (in feet) was determined for the driver’s assigned caution sign. The data in the following table are based on the results of the experiment. a. the response variable b. the factors c. the levels of each factor d. the number of treatment combinations e. the experimental units f. the number of…

A researcher is curious about whether there is a relationship between how much a person enjoys the music of Nickelback (on a 0-12 scale, 0 indicating no enjoyment and 20 indicating maximum enjoyment) and how much a person enjoys films starring Nicolas Cage (on the same 0-20 scale). The following information was gathered from 10 participants:   Nickelback Nicolas Cage 4 7 12 7 6 6 19 15 0 12 5 9 2 1 13 10 16 20 1 8   Make a scatter diagram: Based on the scatter diagram you made, what type of correlation do you assume?   Question 9Select one: a. No Correlation  b. Positive Correlation  c. Negative Correlation   Calculate the Correlation Coefficient  df =  Question 10Select one: a. 10 b. 9 c. 8 d. 7   cutoff score = ? Question 11Select one: a. +/-2.101 b. +/-2.306 c. -.632 d. +2.306 e. +/- .632   r = ? Question 12Select one: a. -.38 b. .92 c.…

A study examined the interactions in a children's museum. (Interactions by visitors to the museum included show-and-tell, learning, teaching, refocusing, participatory play, advocating, and disciplining interactions.) Researchers observed a sample of 180 meaningful interactions, of which 86 were led by children and 94 were led by adult caregivers. Complete parts a through d below. a. Give a point estimate of the true proportion of all meaningful interactions in a children's museum that are led by children. The point estimate is. (Type an integer or decimal rounded to three decimal places as needed.)

Practice question #1. Researchers at the University of Utah carried out a study to see if the size of the fork used to eat dinner influences how much food is consumed. The researchers assigned people to one of two groups. One group ate dinner using a small fork, and the other group ate using a large fork. The researchers found that thatthose who ate with a large fork ate less food on their plate than those who ate with a small fork. An articledescribing this study was called “Dieters Should Use a Big Fork”, implying cause-and-affect andgeneralizing this finding to the population of dieters.  A. Under what circumstances would it be reasonable to conclude a cause-and-effect relationship between fork size and amount eaten? B. Under what circumstances would it be reasonable to generalize this finding to the population of dieters? Why is it often NOT appropriate to generalize the results of experiments to a wider population?

Section 3.1, question 3

A researcher is conducting an experimental study on the effect of aspirin on heart attack risk. In order to assign who will receive aspirin and who will receive a placebo, she first divides her study into three age groups (18-29, 30-49, and 50 or older). She then randomly assigns individuals within these age groups to either receive aspirin or the placebo. This is an example of a cluster ?

A study was conducted to determine whether big-city and small-town dwellers differed in their helpfulness to strangers. In this study, the investigators rang the doorbells of strangers living in a large City or small towns in the vicinity. They explained they had misplaced the address of a friend living in the neighbourhood and asked to use the phone. The following data show the number of individuals who admitted or did not admit the strangers (the investigators) into their homes: Helpfulness to strangers   Admitted strangers into their home  Didnot admit strangers into their home  Big city dwellers 60 90 Small town dwellers 70 30 State the dependent and independent variable  Is this a directional or non directional

California insurance companies wanted to study factors (e.g., the proximity to a major earthquake fault line) that may influence homeowners’ decisions to purchase earthquake insurance. Surveys were mailed to randomly selected households in three California counties to investigate the possible proximity effect. The data collected are shown below:                          Los Angeles        San Bernardino         Santa Clara sample size     1,000                      1,400                         1,200 Number with     377                       469                            390 earthquake insurance   Los Angeles County is located closest among the three to a major earthquake fault line. Are homeowners in Los Angeles County more likely to purchase earthquake insurance than those in San Bernardino County? Test using α = 0.05. (Optional) Are homeowners in Los Angeles County more likely to purchase earthquake insurance than those in Santa Clara County? Use α = 0.05.