We use the t distribution for the statistical inference of the population mean when the underlying population standard deviation is not known. under the assumption that the population is normally distributed, find tα/2,df for the following scenarios. use table 2. (round your answers to 3 decimal places.) tα/2,df
a. a 90% confidence level and a sample of 28 observations.
b. a 95% confidence level and a sample of 28 observations.
c. a 90% confidence level and a sample of 15 observations.
d. a 95% confidence level and a sample of 15 observations

Step-by-step explanation:

Since population std deviation is not  known, we use t critical value for testing of hypothesis.

a) 90% conf level when n =28

df = 27, t critical = 1.706

b) 95% 28

df =27 and t critical = 2.052

c) 90% and 15

df =14 and t critical = 1.761

d) 95% and n =15

df =14:   t critical = 2.145

1. is 4 and 2. is 3

step-by-step explanation:

so if you look at the first one you see that 1 is to 4 and 2 is to 8 and so on, so you can see for every 1 there is a times 4 so if it were 3 then it would be 3*4 and it is 12

for number 2 it is 3 because 1 is to 3 and 2 is to 6 so for every 1 there is 3 so if it were 3 then there would be 3*3 = 9

i think c. but don't trust it.

step-by-step explanation: