What net charge does DNA have?

A review article is a synthesis of research already conducted in various primary literature sources on a specific topic. 

How many new daughter cells are created from one original cell at the end of cell division by mitosis?

Which organism did you observe the five phases of mitosis by looking at prepared slides of the root tips?

For sample sizes greater than 30, the sampling distribution of the mean will be approximately normally distributed

The following sample was taken from a normally distributed population: 20, 27, 15, 20, 16, 22, and 13. A 95% confidence interval for the population mean using this sample is:

A large Midwestern university is interested in estimating the mean time that students spend at the student recreation center per week. A previous study indicated that the standard deviation in time is about 40 minutes per week. If the officials wish to estimate the mean time within ± 10 minutes with a 90 percent confidence, what should the sample size be?

A 95% confidence interval estimate for a population mean μ is determined to be 65.48 to 76.52. If a 90% confidence interval for μ is constructed, it must be: 

If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute, find the point in the distribution in which 75.8% of the college students exceed when trying to find a parking spot in the library parking lot.

If a sample has 20 observations and a 90% confidence estimate for μ is needed, the appropriate critical value is: