In: Statistics and Probability
The daily returns for a stock over a period of 110 days are recorded, and the summary descriptive statistics are given as follows:
Descriptive Statistics: return
Variable | N | N* | Mean | SE Mean | StDev | Minimum | Q1 | Median | Q3 | Maximum |
Return | 110 | 0 | 0.000983 | .00296 | .03103 | -.19992 | -.01393 | .00322 | .01591 | .09771 |
a) Find a 95% confidence interval estimate for μ, where μ is the population mean rate of return of the stock.
b) Test the hypothesis Ho:μ= 0 versus Ha:μ > 0 at 5% significance level.
What is the p-value for the test
Given,
Sample size : n = 110
Sample mean : = 0.000983
Sample standard deviation : s= 0.03103
Confidence interval estimate for , where is the population mean when population standard deviation is not known
for 95% confidence level = (100-95)/100 =0.05
/2 = 0.05/2 =0.025
degrees of freedom = n-1 =110-1=109
t/2,n-1 = t0.025,109 = 1.982
95% confidence interval estimate for , where is the population mean rate of return of the stock
95% confidence interval estimate for , where is the population mean rate of return of the stock = (-0.00488372 ,0.00684972 )
b)
Ho:μ= 0 versus Ha:μ > 0
Right tailed test
For Right tailed test:
For 109 degrees of freed, P(T>0.3321) = 0.3702
p-value = P(t>0.3321) =0.3702
p-value = 0.3702
As
P-Value i.e. is greater than Level of significance i.e
(P-value:0.3702 > 0.05:Level of significance); Fail to Reject
Null Hypothesis