Question

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):

74

102

133

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

a)     Using Excel fuction we calculate mean and standard deviation.

Sample Mean (x) = =AVERAGE(74,102,133,120,60,64) = 92.2

X = 92.2 lb

Sample standard deviation (s) = =STDEV.S(74,102,133,120,60,64) = 30.6

s = 30.6 lb

b)    To find 75% confidence interval we have to find t critical value

t _0.125,5 = 1.301

75% confidence interval = X ± t _0.125,5* s/ √n = 92.2 ± 1.301* 30.6/ √6 = (75.9, 108.5)

            Lower Limit = 75.9 lb

            Upper Limit = 108.5 lb