Often the percent of an animal species in the wild that survive to breed again is lower following a successful breeding season. This is part of nature‘s self- regulation, tending to keep population stable. A study of merlins (small falcons) in northern Sweden observed the number of breeding pairs in an isolated area and the percent of makes (banded for identification) who returned the next breeding season. Here are the data for nine year.
Breeding pairs
28 29 29 29 30 32 33 38 38
Percent Returns
82 83 70 61 69 58 43 50 47
1.Is there a clear explanatory variable and response variable in this setting? If so, tell which is which, If not, explain why not.
2. How would you describe the form of the relationship?
3.do you expect the correlation to be positive or negative? Near + or not? Explain.
1. In this setting, the number of breeding pairs could be considered the explanatory variable, as it is the factor that may have an influence on the percent of males returning for the next breeding season, which would be the response variable.
2. The form of the relationship between the number of breeding pairs and the percent of males returning appears to be a decreasing or negative trend.
3. One would expect the correlation to be negative. As the number of breeding pairs increases, the available resources might become limited, leading to a decrease in the percent of males returning. Since the form of the relationship is decreasing, it indicates that as the number of breeding pairs increases, the percent of males returning tends to decrease as well. The correlation is likely to be near - as the relationship between the variables seems to be fairly strong.
1. In this setting, the explanatory variable is the number of breeding pairs of merlins in the isolated area, while the response variable is the percent of males (banded for identification) that return the next breeding season.
2. The form of the relationship between the number of breeding pairs and the percent of males that return can be described as a decreasing or negative relationship. As the number of breeding pairs increases, the percent of males that return decreases.
3. The correlation between the number of breeding pairs and the percent of males that return is expected to be negative. The more successful the breeding season (i.e., larger number of breeding pairs), the lower the percent of males that return to breed again. The negative correlation suggests that there is competition for resources and mates, resulting in a lower survival rate for males. The correlation is likely to be near negative one (-1) as the decrease in the percent of males that return appears to be quite consistent with an increase in the number of breeding pairs.
1. In this setting, the explanatory variable is the number of breeding pairs of merlins in the isolated area, and the response variable is the percentage of male merlins who return in the next breeding season.
2. The form of the relationship between the number of breeding pairs and the percentage of male merlins returning is not immediately clear without further analysis. To determine the form of the relationship, you would need to create a scatter plot of the data points and visually assess the pattern.
3. Based on the given statement that "the percent of an animal species in the wild that survive to breed again is lower following a successful breeding season," it can be inferred that as the number of breeding pairs increases, the percentage of males who return may decrease. Therefore, one would expect a negative correlation between the number of breeding pairs and the percentage of males returning. The correlation is likely to be negative, but you cannot determine whether it is near + (close to zero) without calculating the correlation coefficient.