Andrew thinks that people living in a rural environment have a healthier lifestyle than other people. he believes the average lifespan in the usa is 77 years. a random sample of 11 obituaries from newspapers from rural towns in idaho gives x¯=79.14 and s=2.48. does this sample provide evidence that people living in rural idaho communities live longer than 77 years? use a 10% level of significance.

Yes, it does.

Step-by-step explanation:

Since the data is approximately Normally distributed and the sample is less than 30, we will be using the Student's t Distribution.

: The life expectancy of people living in rural Idaho is 77 years

: The life expectancy of people living in rural Idaho is greater than 77 years.

So, this is a right-tailed test.

Our t-statistic is given by

where

= 79.14 is the mean of the sample

= 77 is the mean of the null hypothesis

s = 2.48 is the sample standard deviation

n = 11 is the sample size

Computing our t-statistic we get

Now, we obtain the critical upper value for a right-tailed test hypothesis corresponding to a 10% level of significance associated with the Student's t Distribution with 10 degrees of freedom (sample size-1). This is a value such that the area under the t distribution to the left of equals 10% = 0.01

We can do it either by looking up a table or a spreadsheet.

In Excel use

TINV(0.2,10)

In OpenOffice Calc use

TINV(0.2;10)

and we would get = 1.3722

Since our t-statistic is greater than we can reject the null hypothesis and say this sample provide evidence that people living in rural Idaho communities live longer than 77 years.

from the figure we get,

the x axis shows   the months and,

the y-axis shows the number of satisfied customer.

each line or each cell in upward direction (y-axis) shows 500.

the appropriate scale for the y - axis is: -

a = 2000 customers

b = 4000 customers

c = 6000 customers

d = 8000 customers

e = 10000 customers

f = 12000 customers

g = 14000 customers