Answer:

Step-by-step explanation:
From the given information;
the probability of getting returned p = 0.1
If eight rings are sold today, what is the probability that fewer than three will be returned;
According to binomial distribution
Binomial distribution is the probability of success or failure of an outcome of an experiment under observation which is usually repeated several trials. Binomial experiments are random experiment with fixed number of repeated experiment. If we cannot predict before head, the outcome of an experiment , the experiment is called a random experiment.
So , using binomial distribution to determine the probability that fewer than three will be returned;
i.e


Answer:
1) 120
2) E (Z) = 12 and Variance of Z = 90
a) 5 liters
Step-by-step explanation:
1. We can find this by suing combinations.
Here n= 10 and r= 3 so n C r
= 10 C 3= 120
2. E(X) = 8 and E(Y) = 3
Z = 2X - 3Y +5
E(Z ) = 2 E (X) - 3(E)(Y) +5 ( applying property for mean)
= 2(8) - 3(3)+ 5 = 16+5-9= 21-9= 12
V(X) = 9 and V(Y) = 6.
V(Z) = E(Z )²- V(X) *V(Y) (applying property for Variance for two variables )
= 144- 54= 90
3. 55 liters contain adulterated milk in 7: 4.
So it contains 4/ 11*55= 20 liters of water
But we want to make it a ratio of 7:6
the water will be 6/13 *55= 25.38 when rounded gives 25 liters of water
So 25- 20 = 5 liters must be added to make it a ratio of 7:6
Answer:
m∠2 = 78°
Step-by-step explanation:
From the given picture,
lines 'm' and 'n' are the parallel lines and line 't' is the transverse line.
∠1 and angle with the measure of 78° are corresponding angles.
Therefore, m∠1 = 78°
m∠1 = m∠2 [Vertical angles are equal]
m∠2 = 78°
Answer:


a. What is the probability that the cost will be more than $450?
We are supposed to find P(x > 450)
Formula : 


Refer the z table :
P(z<0.9431)=0.8264
P(z> 0.9431)=1-P(z<0.9431)=1- 0.8264= 0.1736
Hence the probability that the cost will be more than $450 is 0.1736
b)What is the probability that the cost will be less than $250?
We are supposed to find P(x<250)
Formula : 


Refer the z table :
P(z<-1.3295)=0.0934
Hence the probability that the cost will be less than $250 is 0.0934
c)What is the probability that the cost will be between $250 and $450?
P(250<z<450)=P(z<450)-P(z<250) = 0.8264 - 0.0934 =0.733
Hence the probability that the cost will be between $250 and $450 is 0.733
d) If the cost for your car repair is in the lower 5% of automobile repair charges, what is your cost?
p = 0.05
refer the z table
z = -1.65
Formula : 




Hence If the cost for your car repair is in the lower 5% of automobile repair charges, so, cost is $221.8
Answer:
(A)6 kilometers
Step-by-step explanation:
First, we determine the value of a using Pythagoras Theorem.

Therefore:
Distance along the long route = 8 + 15 =23 km
Distance along the shortcut =17 km
Difference =23-17 =6km
Therefore, Mr. Jones bikes 6km less when he takes the shortcut instead of the long route.