# Tutor profile: Keaton P.

## Questions

### Subject: Spanish

How do you conjugate the verb "to eat" in Spanish?

Yo como Tu comes Usted come El come Ella come Ellos comen Nosotros comemos Ustedes comen Vosotros comeis

### Subject: Basic Math

What are some tricks to help me remember general math concepts?

To change a percent to a decimal, move the decimal point two places to the left and drop the percent sign. To change a decimal to a percent, move the decimal point two places to the right and attach a percent sign. Calculate simple percents by dividing. For example, to find 50% (half) of a number, divide by 2; to find 25%, divide by 4; to find 20%, divide by 5, etc. You can calculate some percents by reversing the numbers. For example 28% of 50 is the same as 50% of 28, which equals 14.

### Subject: Statistics

Fifty people were weighed before starting a 6 month dieting program and again after they completed it. The researchers found the change in weight by taking the before weight minus the after weight. The test statistic was calculated to be 3.55. What is the correct conclusion?

We have strong statistically significant evidence to show that the population mean change in weight was greater than zero. This is a paired t test because we use data from related groups, i.e. the same person is weighed twice. And we use a paired t-test to determine whether the mean difference between two groups is statistically significantly different to zero. We are given the test statistic in the problem, so this is a conceptual question. In statistics there is a rule of thumb when interpreting values: 68 95 99.7 Rule About 68% of values fall within one standard deviation of the mean. About 95% of the values fall within two standard deviations from the mean. Almost all of the values — about 99.7% — fall within three standard deviations. Our test statistic was calculated to be 3.55, a value that is beyond the 99.7% rule, which leads us to the conclusion that there is strong statistically significant evidence to show that the population mean change in weight was greater than zero.

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