What will happen to the sizes of the populations in the food web if the sea otter disappears?
What will happen to the sizes of the populations in the food web if the sea otter disappears?
What will happen to the sizes of the populations in the food web above if the sea otter disappears? Large fish increase and sea urchins decrease.
Which of the following is the best definition of a population?
A population is the number of organisms of the same species that live in a particular geographic area at the same time, with the capability of interbreeding. For interbreeding to occur, individuals must be able to mate with any other member of a population and produce fertile offspring.
Which of the following is composed of a population of a species plus populations of other species?
An ecological community consists of all the populations of all the different species that live together in a particular area. Interactions between different species in a community are called interspecific interactions—inter- means “between.”
Which of the statements give the reason why a pyramid of energy is narrower at the top than at the bottom?
In other words, an energy pyramid shows how much energy is available at each trophic level. Each level above gets smaller, because as energy is lost as heat, there is less energy avail- able as food for organisms. The longer the food chain, the more energy is lost between the bottom and top links.
How do you interpret the p value?
The smaller the p-value, the stronger the evidence that you should reject the null hypothesis.
- A p-value less than 0.05 (typically ≤ 0.05) is statistically significant.
- A p-value higher than 0.05 (> 0.05) is not statistically significant and indicates strong evidence for the null hypothesis.
What is a condition in a study?
a level of the independent variable that is manipulated by the researcher in order to assess the effect on a dependent variable. Participants in an experimental condition receive some form of treatment or experience whereas those in a control condition do not.
How do you check for nearly normal conditions?
Nearly Normal:
- If you have raw data, graph a histogram to check to see if it is approximately symmetric and sketch the histogram on your paper.
- If you do not have raw data, check to see if the problem states that the distribution is approximately Normal.
What is meant by the 95% confidence interval of the mean?
A 95% confidence interval is a range of values that you can be 95% certain contains the true mean of the population. This is not the same as a range that contains 95% of the values. The 95% confidence interval defines a range of values that you can be 95% certain contains the population mean.
What if the sample size is less than 30?
For example, when we are comparing the means of two populations, if the sample size is less than 30, then we use the t-test. If the sample size is greater than 30, then we use the z-test.
What test statistics is appropriate to use when the sample size is less than 30?
Most of the Statistical book shows when sigma is known and less than 30 sample size then z-test is appropriate.
How does sample size affect t test?
The sample size for a t-test determines the degrees of freedom (DF) for that test, which specifies the t-distribution. The overall effect is that as the sample size decreases, the tails of the t-distribution become thicker.
Which test is used when sample size is more than 30?
z-test