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
It is 40 because 8*5 is 40
Answer:
I believe answer B
Step-by-step explanation:
It says shifted UP 3 units and 2+3=5 so that is my answer. Feel free to yell at me if I am wrong.
$18.95 x 15/100 is equal to 2.84
18.95 - 2.84 is equal to $16.11
Hope that helped! :)