Question

A. The method of tree ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution.

1278

1257

1250

1194

1268

1316

1275

1317

1275

(a) Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviation s. (Round your answers to the nearest whole number.)

x =	A.D.
s =	yr

(b) Find a 90% confidence interval for the mean of all tree ring dates from this archaeological site. (Round your answers to the nearest whole number.)

lower limit	A.D.
upper limit	A.D.

B. How much do wild mountain lions weigh? Adult wild mountain lions (18 months or older) captured and released for the first time in the San Andres Mountains gave the following weights (pounds):

75

107

127

120

60

64

Assume that the population of x values has an approximately normal distribution.

(a) Use a calculator with mean and sample standard deviation keys to find the sample mean weight x and sample standard deviation s. (Round your answers to one decimal place.)

x =	lb
s =	lb

(b) Find a 75% confidence interval for the population average weight μ of all adult mountain lions in the specified region. (Round your answers to one decimal place.)

lower limit	lb
upper limit	lb

Answer 1

30,9 A 1a) X : (x-)2 64 : 169 4oo 5776 1278 1257 1950 1194 1268 1316 1275 1317 1975 4. 2116 . 25 - 2269 25 10788 since 7 = Exiiz 1970 Standard deviation 13(x1-)2 - 110788 - n- i 9-1 = 36.7219 ~ 37

☺ = 8 90% confidence Internal : = (x = text { x=0.1 and df = 1-1= 9-1 =(1220 + 1.36X 32) = (1970 * 221934) = (1247.066,1292934) Lower limit = 1247 upper limit = 1293 75 107 127 (x-x)2 294.695 22.0:026 1213.358 774.692 1034.696 793-363 120 60 64 sample mean = Standard deviation 99.16 ~ 92.2 = {(x* -* )2 = 14330833 6-1 not = 29.43 ~ 29.4 - 6 75% Confidence intervalo S:4:0.25, df 25 - 192.2 1 1301X29.4) 192.9 + 1.30) x 29.4 V6

= 192.2 + 15.615.) = 176.5851107.815) lower upper limit limit = = 76.6 107.8