A study by TSU concluded that 45% of college students sleep at least 8 hours per night ...

A study by TSU concluded that 45% of college students sleep at least 8 hours per night. In a sample of 10 PSU students, find the probability that:
a. exactly 4 of the 10 get 8 hours or more.
b. at least 8 of the 10 get 8 or more.

Hemoglobin [Hgb] is a protein that transports both O2 & CO2. Because Bus 220 students often appear semi-comatose in class, it is thought that their Hgb level may be reduced by the topics presented in the course. Test the research assertion that the mean Hgb level for MAT 210 students is higher than that of Bus 220 students. Use the data shown below.
n xbar σ
BUS 220 50 11.6 4.2 α = .004
MAT 210 40 13.7 2.9