Question

1. 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.

10.1 8.8 10.5 8.7 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

2. At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. Wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. The cyclic nature of wind and moving sand determines the shape and location of large dunes. At a test site, the prevailing direction of the wind did not change noticeably. However, the velocity did change. Fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. Based on long-term experience, σ can be assumed to be 275 cm/sec.

(a) Find a 95% confidence interval for the population mean wind speed at this site. (Round your answers to the nearest whole number.)

lower limit:	cm/sec
upper limit:	cm/sec

Answer 1

Question 1

	Values ( X )
	10.1	0.0025
	8.8	1.5625
	10.5	0.2025
	8.7	1.8225
	9.4	0.4225
	9.8	0.0625
	10	0.0025
	9.9	0.0225
	11.2	1.3225
	12.1	4.2025
Total	100.5	9.625

Mean

Standard deviation

Part b)

Confidence Interval



Lower Limit =
Lower Limit = 8.4866
Upper Limit =
Upper Limit = 11.6134
99.9% Confidence interval is ( 8.49 , 11.61 )

Question 2

Confidence Interval :-



Lower Limit =
Lower Limit = 1004.8295
Upper Limit =
Upper Limit = 1145.1705
95% Confidence interval is ( 1005 , 1145 )