Answer:
P(A) = 0.57 (to the nearest hundredth)
Step-by-step explanation:
There are 7 letters in total
4 of them are the letter A
⇒ P(A) = 4/7
= 0.5714285714...
= 0.57 (to the nearest hundredth)
The product of 9 and 12 is 108
Answer:

The degrees of freedom are given by:
Now we can calculate the p value with the following probability:

And for this case since the p value is lower compared to the significance level
we can reject the null hypothesis and we can conclude that the true mean for this case is different from 30.6 at the significance level of 0.05
Step-by-step explanation:
For this case we have the following info given:
represent the sample mean
represent the sample deviation
represent the reference value to test.
represent the sample size selected
The statistic for this case is given by:

And replacing we got:

The degrees of freedom are given by:
Now we can calculate the p value with the following probability:

And for this case since the p value is lower compared to the significance level
we can reject the null hypothesis and we can conclude that the true mean for this case is different from 30.6 at the significance level of 0.05
Answer:
x^2 +20x+100
Step-by-step explanation:
(x+10)^2
(x+10) (x+10)
FOIL
first:x*x = x^2
outer: x*10
Inner 10*x
last: 10*10 =100
Add them together
x^2+10x+10x+100
x^2 +20x+100