Can someone explain to me how to do these, i dont get it.

a hair stylist worked from 8: 45 a. m. until 12: 15 p. m. and 12: 45 p. m. until 5: 15 p. m. estimate the total number of hours worked.

8 hr

7 hr 15 min

8 hr 15 min

7 hr 30 min

Complete the equation of the line through (−10,3) and (−8,−8). use exact numbers.

3. a sum of $2700 is to be given in the form of 63 prizes. if the prize is of either $100 or $25, find the number of prizes of each type.

Arandomized controlled trial is designed to evaluate the effect of metoprolol in patients with heart failure. while preparing for statistical analysis, the researcher reviews some common types of statistical errors. which of the following statements is true regarding a type i error in a clinical study? a. the study is not significantly powered to detect a true difference between study groups. bthe null hypothesis is true but is rejected in error. c. the null hypothesis is false but is accepted in error. d. type i error is also known as beta and is usually 0.1 or 0.2. e. type i error depends on the study's confidence interval.