Answer:
A one-sample t-interval for a population mean
Step-by-step explanation:
As the question is "How many minutes per day, on average, do you spend visiting social media sites?", the answer will be in a numerical form (number of hours, positive integer or real number).
As this is not a proportion, the option "A one-sample t-interval for a population mean" is discarded.
As the study does not defined another variable to compare in pairs, it is not a matched-pairs test. Option "A matched-pairs t -interval for a mean difference" discarded.
There are not two means in the study, so there is no "difference between means" variable. Options "A two-sample z-interval for a difference between proportions" and "A two-sample t-interval for a difference between means".
This should be a one-sample t-interval for a population mean, as there is only one sample, one population mean and the population standard deviation is not known.
Connor has 16 nickels. If you have 9 dimes (90 cents) and you doubled it that would give you 18 quarters ($4.50). you have 7 more nickels than dimes, so you do 7+9 which equals 16 nickels (80 cents). 90+450+80=620.
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
I believe the answer is x is greater or equal to 54.9 (x=width)