A nonprofit organization is asking for donations. It hopes to design an email campaign that will ensure it receives at least $50,000. The campaign will reach 10,000 donors and receive donations with a mean of $10 and a standard deviation of $5. Which measure should be used to determine the probability of the campaign receiving $50,000?

The median represents the middle value of a data set when arranged in order. While it can provide information about the central tendency of donations, it does not account for variability or the distribution of donations, making it ineffective for calculating probabilities in this context.

R-squared is a statistical measure that indicates the proportion of variance in a dependent variable that can be explained by an independent variable in regression analysis. It is not applicable in this situation because the campaign's goal is to determine the probability of total donations, not to assess the fit of a regression model.

The T-statistic is used in hypothesis testing to determine if the mean of a sample significantly differs from a hypothesized population mean, particularly when sample sizes are small. In this case, since the sample size is large (10,000 donors), the Z-score is more appropriate than the T-statistic for evaluating probabilities related to the campaign's total donations.