Asimple random sample of size nequals40 is drawn from a population. the sample mean is found to be 103.9, and the sample standard deviation is found to be 21.9. is the population mean greater than 100 at the alphaequals0.05 level of significance?

There is enough evidence to support the claim that the population mean is greater than 100

Step-by-step explanation:

Step 1: We state the hypothesis and identify the claim

and (claim)

Step 2: Calculate the test value.

Step 3: Find the P-value. The p-value obtained from a calculator is using d.f=39 and test-value 1.126 is 0.134

Step 4: We fail to reject the null hypothesis since P-value  is greater that the alpha level. (0.134>0.05).

Step 5: There is enough evidence to support the claim that the population mean is greater than 100.

Alternatively: We could also calculate the critical value to obtain +1.685 for and d.f=39 and compare to the test-value:

The critical value (1.685>1.126) falls in the non-rejection region. See attachment.

NB: The t- distribution must be used because the population standard deviation is not known.

this doesn't make sense lol

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.