Question

Suppose 45% of the worlds population has type "O" blood type. A study was done to see if the percent differs for college students. 47% of the 1000 random selected college students have type O blood. conduct a hypothesis test to determine if the percent of college students with type o blood differs for college students?

Answer 1

We accept H₀, with CI = 90 %, porcentage of O blood type in college students does not differ from the world population porcentage

Explanation:

The test is a proportion two-tail test ( note: differs)

p₀ = 45 % or p₀ = 0,45

n = 1000

p = 47 % or p = 0,47

Test Hypothesis

Null hypothesis H₀ p = p₀

Alternative hypothesis Hₐ p ≠ p₀

CI we assume 90 % then α = 10 % α = 0,1 α/2 = 0,05

z score from z-table z(c) = 1,64

To calculate z(s) = ( p - p₀ ) / √ p₀q₀/ n

z(s) = ( 0,47 - 0,45 )/ √( 0,45)*(0,55)/1000

z(s) = 0,02/√( 0,2475)/1000

z(s) = 0,02/0,01573

z(s) = 1,2714

Now we compare z(s) and z(c)

z(s) < z(c) 1,2714 < 1,64

Then z(s) is in the acceptance region we accept H₀