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):

71

104

126

121

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

What percentage of hospitals provide at least some charity care? Based on a random sample of hospital reports from eastern states, the following information is obtained (units in percentage of hospitals providing at least some charity care):

57.3

56.5

52.9

66.2

59.0

64.7

70.1

64.7

53.5

78.2

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 percentage x and the sample standard deviation s. (Round your answers to one decimal place.)

x =	%
s =	%

(b) Find a 90% confidence interval for the population average μ of the percentage of hospitals providing at least some charity care. (Round your answers to one decimal place.)

lower limit	%
upper limit

Answer 1

1)

from given data and excel:

x =average (data array )=91.00

s =stdev(data array) =29.6

b)

std error ='sx=s/√n=29.611/√6=

12.089

for 75% CI; and 5 df, critical t=		1.301
margin of error E=t*std error                            =		15.727
lower bound=sample mean-E =		75.3
Upper bound=sample mean+E=		106.7

2)

a)

x =average (data array )=62.3

s =stdev(data array) =8.0

b)

for 90% CI; and 9 df, critical t=		1.833	from excel: t.inv(0.95,9)
margin of error E=t*std error                            =		4.636
lower bound=sample mean-E =		57.7
Upper bound=sample mean+E=		66.9