A local hospital is piloting a program to see if they can cure patients with a fear of spiders using therapy
sessions. Typically, 9 or 10 therapy sessions are
needed before the improvement is noticed. An
experimenter wants to test if using a new drug, D-
anthamine, would help patients cure their fear of
spiders in fewer therapy sessions.
Each of the 27 people involved in the study received a
pill before each of two therapy sessions. 17 of the 27
people were randomly assigned the D-anthamine pill
while the remaining 10 received a placebo. After the
two therapy sessions, none of the patients received
additional pills or therapy. Three months after the
administration of the pills and the two therapy sessions,
each of the 27 people were evaluated to see if their
fear of spiders had improved.
a. Was this an experiment or an observational
study? Provide justification for your choice.

In tossing one coin 10 times, what are your chances for tossing a head? a tail? 2. in tossing one coin 100 times, what are your chances for tossing a head? a tail? 3. in tossing one coin 200 times, what are your chances for tossing a head? a tail? deviation = ((absolute value of the difference between expected heads and observed heads) + (absolute value of the difference between expected tails and observed tails)) divided by total number of tosses. this value should always be positive. 4. what is the deviation for 10 tosses? 5. what is the deviation for the 100 tosses? 6. what is the deviation for 200 tosses? 7. how does increasing the total number of coin tosses from 10 to 100 affect the deviation? 8. how does increasing the total number of tosses from 100 to 200 affect the deviation? 9. what two important probability principles were established in this exercise? 10. the percent of occurrence is the obtained results divided by the total tosses and multiplied by 100%. toss the coins 100 times and record your results. calculate the percent occurrence for each combination. percent head-head occurrence: percent tail-tail occurrence: percent head-tail occurrence:

Sally deposited money into a savings account paying 4% simple interest per year.the first year,she earn $75 in interest.how much interest will she earn during the following year?

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. the design of the study justifies the assumption that the sample can be treated as a simple random sample. use the data to construct a 99% confidence interval estimate of μ, the mean duration of game play. 4028 4316 4816 4650 4036 5010 4833 4331 4307