Please check part C (2 points) The drying time of a certain type of paint under
ID: 3325272 • Letter: P
Question
Please check part C
(2 points) The drying time of a certain type of paint under specified test conditions is known to be normally distributed with mean value 80 min and standard deviation 10 min. Chemists have proposed a new additive designed to decrease average drying time. It is believed that drying times with this additive will remain normally distributed with 10 Because of the expense associated with he additive evidence should st na gest a m rover e average di in me e ore such a clusion adopted. Let denote the true average drying time when the additive is used. The hypotheses Ho : 80 versus HA :Explanation / Answer
a)
One-Sample Z
Test of = 80 vs < 80
The assumed standard deviation = 10
N Mean SE Mean 96% Upper Bound Z P
34 78.00 1.71 81.00 -1.17 0.122
A) do not reject Ho
b) 0.002
c)
Power and Sample Size
1-Sample Z Test
Testing mean = null (versus < null)
Calculating power for mean = null + difference
= 0.04 Assumed standard deviation = 10
Sample
Difference Size Power
-5 34 0.877948
beta = 1 - power = 1-0.877948 =0.122052
d)
Power and Sample Size
1-Sample Z Test
Testing mean = null (versus < null)
Calculating power for mean = null + difference
= 0.04 Assumed standard deviation = 10
Sample Target
Difference Size Power Actual Power
-5 67 0.99 0.990409
n = 67