Agricultural experts are trying to develop a bird deterrent to reduce costly damage to crops in the United States. An experiment is to be conducted using garlic oil to study its effectiveness as a nontoxic, environmentally safe bird repellant. The experiment will use European starlings, a bird species that causes considerable damage annually to the corn crop in the United States. Food granules made from corn are to be infused with garlic oil in each of five concentrations of garlic ?0 percent, 2 percent, 10 percent, 25 percent, and 50 percent. The researchers will determine the adverse reaction of the birds to the repellant by measuring the number of food granules consumed during a two-hour period following overnight food deprivation. There are forty birds available for the experiment, and the researchers will use eight birds for each concentration of garlic. Each
bird will be kept in a separate cage and provided with the same number of food granules.
(a) For the experiment, identify
i. the treatments
ii. the experimental units
iii. the response that will be measured
(b) After performing the experiment, the researchers recorded the data shown in the table below.
Garlic oil concentration
Mean number of food granules consumed
Number of birds
i. Construct a graph of the data that could be used to investigate the appropriateness of a linear regression model for analyzing the results of the experiment. ii. Based on your graph, do you think a linear regression model is appropriate? Explain.2. A local radio station plays 40 rock-and-roll songs during each 4-hour show. The program director at the station needs to know the total amount of airtime for the 40 songs so that time can also be programmed during the show for news and advertisements. The distribution of the lengths of rock-and-roll songs, in minutes, is roughly symmetric with a mean length of 3.9 minutes and a standard deviation of 1.1 minutes. (a) Describe the sampling distribution of the sample mean song lengths for random samples of 40 rock-and-roll songs. (b) If the program manager schedules 80 minutes of news and advertisements for the 4-hour (240-minute) show, only 160 minutes are available for music. Approximately what is the probability that the total amount of time needed to play 40 randomly selected rock-and-roll songs exceeds the available airtime? 3. A humane society wanted to estimate with 95 percent condence the proportion of households in its county that own at least one dog. (a) Interpret the 95 percent condence level in this context. The humane society selected a random sample of households in its county and used the sample to estimate the proportion of all households that own at least one dog. The conditions for calculating a 95 percent condence interval for the proportion of households in this county that own at least one dog were checked and veried, and the resulting condence interval was 0.417 i 0.119. (b) A national pet products association claimed that 39 percent of all American households owned at least one dog. Does the humane society's interval estimate provide evidence that the proportion of dog owners in its county is different from the claimed national proportion? Explain. (c) How many households were selected in the humane society's sample? Show how you obtained your answer. 1. Agricultural experts are trying to develop a bird deterrent to reduce costly damage to crops in the United States. An experiment is to be conducted using garlic oil to study its effectiveness as a nontoxic, environmentally safe bird repellant. The experiment will use European starlings, a bird species that causes considerable damage annually to the corn crop in the United States. Food granules made from corn are to be infused with garlic oil in each of ve concentrations of garlic 0 percent, 2 percent, 10 percent, 25 percent, and 50 percent. The researchers will determine the adverse reaction of the birds to the repellant by measuring the number of food granules consumed during a two-hour period following overnight food deprivation. There are forty birds available for the experiment, and the researchers will use eight birds for each concentration of garlic. Each bird will be kept in a separate cage and provided with the same number of food granules. (a) For the experiment, identify i. the treatments ii. the experimental units iii. the response that will be measured (b) After performing the experiment, the researchers recorded the data shown in the table below. Garlic oil concentration 0% 2% 10% 25% 50%
