In: Statistics and Probability
The Nellie Mae organization found that in a random sample of 100 undergraduate students taken in 2004, the average credit card balance was $2169. Suppose sample standard deviation of these credit card balances is $1000. Perform a test to test if the average credit card debt exceeds $2000.
a)
Identify the population
Identify the variable:
Identify the parameter
b)
Calculate T stat
Find P-value with DF
a)
population : undergraduate students
varibale : credit card balance
parameter : average credit card debt
.......
b)
Ho : µ = 2000
Ha : µ > 2000
(Right tail test)
Level of Significance , α =
0.05
sample std dev , s =
1000.0000
Sample Size , n = 100
Sample Mean, x̅ = 2169.0000
degree of freedom= DF=n-1=
99
Standard Error , SE = s/√n = 1000.0000 / √
100 = 100.0000
t-test statistic= (x̅ - µ )/SE = (
2169.000 - 2000 ) /
100.0000 = 1.69
p-Value = 0.0471 [Excel
formula =t.dist(t-stat,df) ]
Decision: p-value<α, Reject null hypothesis
..................
THANKS
revert back for doubt
please upvote