There is no work to show. It is really just trial and error till you get the hang of it. You look at the multiples of the last term and find.which add or subtract to the middle terms coefficient. Use DeCartes law of signs to determine if it is plus or minus.
1. Does not factor solve using other method
2. (X-5)^2
Answer:
a) 

And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %
b) 

So one deviation below the mean we have: (100-68)/2 = 16%
c) 

For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%
Step-by-step explanation:
For this case we have a random variable with the following parameters:

From the empirical rule we know that within one deviation from the mean we have 68% of the values, within two deviations we have 95% and within 3 deviations we have 99.7% of the data.
We want to find the following probability:

We can find the number of deviation from the mean with the z score formula:

And replacing we got


And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %
For the second case:


So one deviation below the mean we have: (100-68)/2 = 16%
For the third case:

And replacing we got:


For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%
Answer:
A t-score of 2.0244 should be used to find the 99% confidence interval for the population mean
Step-by-step explanation:
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 39 - 1 = 38
Now, we have to find a value of T, which is found looking at the t table, with 38 degrees of freedom(y-axis) and a confidence level of 0.99(
). So we have T = 2.0244.
A t-score of 2.0244 should be used to find the 99% confidence interval for the population mean
R2+15r+36=0 the answer is r=6
The Answer is 21 because 7 and 3 can go in it as well