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
Answer:
First awnser
Step-by-step explanation:
4x(7-v2)+v7(7-v2)
28-4v2+7v7-v14
Answer:
Option (B)
Step-by-step explanation:
Domain of function is defined by the set of x-values (input values) and Range of a function is a set of y-values (output values).
From the graph attached,
Domain of f(x) → Set of all real numbers
Range of f(x) → y-values > 0
Domain of 
→ Set of all real numbers
Range of → y < 2
Therefore, domain of both the functions is a set of all real numbers.
Option (B) is the correct option.
Answer:
units.
Therefore, Option C is correct.
Step-by-step explanation:
We have given a pentagon ABCDE
We need to calculate its length
That means we have to find the distance of AD
So, coordinates of A(1,6) and D(4,-2)
Using distance formula:
Here,
On substituting the values we will get:
On simplification:
.
Hence, the length of AD is units.
Therefore, Option C is correct.
5x+7y=25
5x-2y=-65
subtract both of the equations
5x-5x=0
7y--2y= 7y+2y=9y
25--65=25+65=90
0+9y=90
9y=90
divide both sides by 9 to get y by itself
9y/9=90/9
cross out 9 and 9 which becomes 1*1*y=y
90/9=10
y=10
find x by using the substitution method
5x+7y=25
5x+7(10)=25
5x+70=25
move +70 to the other side
sign changes from +70 to -70
5x+70-70=25-70
5x=-45
divide both sides by 5 to get x by itself
5x/5=-45/5
cross out 5 and 5 then becomes 1*1*x=x
-45/5=-9
x=-9
answer:
(-9,10)
