im having a hard time with this one, the 99.9 and where to get numbers for upper and lower and giving me a tough time. this week we are focusing on using excel for these but i cant seem to get it correct.

1.)Use a calculator with mean and sample standard deviation keys to find the sample mean readingand the sample standard deviations. (in mg/dl; round your answers to two decimal places.)

X hat=10.13

s=.99

Find a 99.9% confidence interval for the population mean of total calcium in this patient's blood. (in mg/dl; round your answer to two decimal places.)

lower limit

upper limit

2.) Supposexhas a distribution with a mean of80and a standard deviation of45. Random samples of sizen=36are drawn.

(a)Describe thex bardistribution.

X bar has a normal distribution.

X bar has a geometric distribution.

x bar has a Poisson distribution.

x bar has an unknown distribution.

x bar has a binomial distribution.

x barhas an approximately normal distribution.

Compute the mean and standard deviation of the distribution. (For each answer, enter a number.)

mu sub x bar =

sigma sub x bar =

(b)Find thezvalue corresponding to X bar=65. (Enter an exact number.)

z=

(c)FindP(x bar <65). (Enter a number. Round your answer to four decimal places.)

P(x bar < 65)=

(d)Would it be unusual for a random sample of size36from thexdistribution to have a sample mean less than65? Explain.

No, it would not be unusual because less than 5% of all such samples have means less than 65.

Yes, it would be unusual because less than 5% of all such samples have means less than 65.

No, it would not be unusual because more than 5% of all such samples have means less than 65.

Yes,it would be unusual because more than 5% of all such samples have means less than 65.