Question

Over the past several months, an adult patient has been treated for tetany (severe muscle spasms). This condition is associated with an average total calcium level below 6 mg/dl. Recently, the patient's total calcium tests gave the following readings (in mg/dl). Assume that the population of x values has an approximately normal distribution. 9.1 8.4 10.3 9.5 9.4 9.8 10.0 9.9 11.2 12.1 (a) Use a calculator with mean and sample standard deviation keys to find the sample mean reading x and the sample standard deviation s. (Round your answers to two decimal places.) x = mg/dl s = mg/dl (b) Find a 99.9% confidence interval for the population mean of total calcium in this patient's blood. (Round your answer to two decimal places.) lower limit mg/dl upper limit mg/dl (c) Based on your results in part (b), do you think this patient still has a calcium deficiency? Explain. Yes. This confidence interval suggests that the patient may still have a calcium deficiency. Yes. This confidence interval suggests that the patient no longer has a calcium deficiency. No. This confidence interval suggests that the patient may still have a calcium deficiency. No. This confidence interval suggests that the patient no longer has a calcium deficiency.

Answer 1

(A) Enter the data into excel sheet, use excel function AVERAGE and STDEV.S to find the mean and standard deviation

mean = AVERAGE(data range) = 9.97

Standard deviation (s) = 1.05

(B) Using TI-84 calculator

Press STAT then TESTS then TInterval

enter the data

x = 9.97

s= 1.05

n = 10 (sample size)

c-level = 0.999

press enter

lower limit = 8.38

upper limit = 11.56

(C) last option is correct, option D because 6 mg/dl is not included in the confidence interval which suggests that the calcium level is above 6mg/dl