Suppose the time of computer usage is assumed to be normally distributed. A random sample of 10 students is taken with sample mean of 9.3 and sample variance of 16.9.

In constructing the confidence interval for mean at 10 percent significance level, which of following statements are TRUE?

IThe lower confidence limitis 6.92

IIThe upper confidence limitis 12.00

IIIThe standard error is 1.299

I and III

I and II

All of the above

III

I