Question

Consider a new drug that is being studied to alter red blood cell (RBC) counts in individuals. The mean number of RBC in normal individuals is 5 million cells per microliter (cells/mcL). A trial study was performed in which some volunteers took the drug and had their RBC numbers counted.

The data is:

4997000 4830000 4986000 4988000 4454000 4961000 5185000 4945000 4807000 5130000 5175000 4811000 5006000 4752000 4997000 4841000 4962000 4723000 4777000 4796000

(a, 2 pts) Which “population” are we really studying with our sample?

(b, 1 pt) What is H0:

(c, 1 pt) What is HA:

(d, 2 pts) What is the sample mean? ?̅ = __________ (provide value to nearest 0.1)

(e, 2 pts) What is the sample standard error? SE = __________ (provide value to nearest 0.1)

(f, 2 pts) What is tcalc? tcalc = __________ (provide value to nearest 0.001)

(g, 2 pts) What is tcrit for significance at the p<0.05 level? tcrit = __________ (provide value to nearest 0.001)

(h, 2 pts) Is the mean RBC value of the volunteers different than expected and, if so, how? Use the grammar described in lecture and state with what degree of confidence you make your conclusion by providing the most specific range of p values from the table provided in lecture. You must use the phrase "significantly smaller", "significantly larger" or "not significantly different" in your answer.

Answer 1

from above

a) red blood cell (RBC) counts in individuals after taking new drug

b)null hypothesis: HO: μ		=	5000000
c) Alternate Hypothesis: Ha: μ		≠	5000000

d)

sample mean 'x̄=

4906150.000

e)

std error 'sx=s/√n=

38621.7

f)

test stat t ='(x-μ)*√n/sx=

-2.430

g)

tcrit =-/+2.093

h)

since test statistic is less than crtiical value , therefore p value <0.05 , we can reject null hypothesis and conclude that RBC after taking new drug is significantly different from 5 million.