West Coast University Statistics Worksheet

YOU MUST COMPLETE ALL 6 STEPS TO THE THREE QUESTIONS Questions are attached bellow

a) State hypotheses and describe the parameter (p)

b) Calculate the test statistic

c) Draw and shade the curve

d) Calculate the p-value

e) State result

f) Write conclusion in context of the problem

Please show your work and explain your answers

Name ___________________________
Period _______
U7-Absent Version At-home Learning
Statistics
You must complete the 6 steps for each question to receive full credit.
1. The makers of a corona virus screening test claims that it will detect the virus in 92% of
people with the disease. 150 randomly selected people who have previously been
diagnosed are given the screening test, and 128 are identified as having the corona
virus. Does this finding provide evidence that the screening test detects the virus at a
rate different from the 92% claimed by the manufacturer?
a) State hypotheses and describe the parameter (p)
b) Calculate the test statistic
c) Draw and shade the curve
e) State result
f) Write conclusion in context of the problem
d) Calculate the p-value
Test Statistic
𝑍=
(𝑝̂ − 𝑝)
√𝑝(1 − 𝑝)
𝑛
2. Suppose a polling organization wants to report their results using a 90% confidence level with a margin of error of
±4 percentage points. Find the number of people they would need to interview.

m = z * 

p (1 − p ) 


n

3. USA Today reported that 37% of adult drivers admit that they often drink coffee when driving. This was based on a
random sample of 115 adult drivers. What is the 93% confidence interval for the true proportion of adult drivers
that often drink coffee while driving? (be sure to include your conclusion statement)
𝑝̂ (1 − 𝑝̂ )
𝐶𝑜𝑛𝑓𝑖𝑑𝑒𝑛𝑐𝑒 𝐼𝑛𝑡𝑒𝑟𝑣𝑎𝑙 = 𝑝̂ ± 𝑧 ∗ √
𝑛