Answer:
The probability of finding a sample mean less than 18 hours is 0.0082
Step-by-step explanation:
To find the probability of finding a sample mean less than 18 hours, we need to calculate the z-score of this sample mean 18. And the probability of finding a sample mean less than 18 hours is P(z<z(18)).
Z-score can be calculated as follows:
z(18)=
where
- X is the sample mean (18 hours)
- M is the average hours dentists spend per week on fillings (20 hours)
- s is the standard deviation (10 hours)
- N is the sample size (144)
Putting the numbers, we get:
z(18)=
Using z- table we can find that P(z<z(18)) = 0.0082
Is this itAnswer:
Step-by-step explanation:
Answer:
a) -1535.5
b) 0
Step-by-step explanation:
A) We do this problem according to its parenthesis. First, let's evaluate the first half, -2[(-1/4)-12(-1)^2]. We have to do (-1)^2 first, because of PEMDAS. (-1)^2 is just 1. Now, our equation is -2[(-1/4)-12*1]. Thus, we get -2[(-1/4)-12] because 12*1 is just 12. Then, we do (-1/4)-12, giving us -12.25. Our equation becomes -2(-12.25). Then, we just get 24.5.
The next half, -5[24+2(-12)^2] is similar. We first evaulate (-12)^2 because of PEMDAS, giving us 144. Then, we have -5[24+2(144)]. 2 times 144 is 288, so we get -5[24+288]. 24 + 288 is 312, so we have -5(312). This finally gives us -1560.
Putting the two together, we get 24.5 - 1560, which is -1535.5.
--------------------------------------------------------------------------------------------------------------B) We substitute a = -1/3 and b = -1 into the equation, -a^2b^2 - 3a^3b^2.
We plug in -1/3 where a is and -1 where b is. So:
-(-1/3)^2(-1)^2 - 3(-1/3)^3(-1)^2.
The tricky part of this problem is making sure you follow PEMDAS. We evaluate the exponents first.
-1/9 * 1 - 3(-1/27) * 1
= -1/9 + 1/9
= 0
Answer:
x > -1
Step-by-step explanation:
The teacher that corrected the greatest amount would be Mr. James. Reason for this would be that 5/8 is .625 and when you move the decimal to places to the right to make a percent, you would get 62%
