Answer: a) Linear function
b) adding 8 each time x increases by 1
c) (0,13)
Step-by-step explanation:
For the given table, the rate of change is constant throughout the table.
The rate of change = 
Similarly we can check for every interval, the rate of change remains constant .
Thus, it is a linear function and the pattern we observe here is "adding 8 each time x increases by 1".
We know that the ordered pair of y intercept = (0,y)
In the table at x=0, y=13
hence, the y intercept of the given function is (0,13)
Answer:
Step-by-step explanation:
When finding the average of a set of numbers, we
- A) Add up all the numbers
- B) Divide that sum by the total number of numbers in the data set
Let's represent this with a formula, s being the sum of all numbers, n being the total number of numbers.
Since we <u>already know the sum</u> and we <u>know how many numbers there are</u> (8), we can substitute inside our expression to find the average.
Therefore, the average of all these numbers is 11.25.
Hope this helped!
We assume the lunch prices we observe are drawn from a normal distribution with true mean 
and standard deviation 0.68 in dollars.
We average 
samples to get 
.
The standard deviation of the average (an experiment where we collect 45 samples and average them) is the square root of n times smaller than than the standard deviation of the individual samples. We'll write
Our goal is to come up with a confidence interval (a,b) that we can be 90% sure contains .
Our interval takes the form of 
as is our best guess at the middle of the interval. We have to find the z that gives us 90% of the area of the bell in the "middle".
Since we're given the standard deviation of the true distribution we don't need a t distribution or anything like that. n=45 is big enough (more than 30 or so) that we can substitute the normal distribution for the t distribution anyway.
Usually the questioner is nice enough to ask for a 95% confidence interval, which by the 68-95-99.7 rule is plus or minus two sigma. Here it's a bit less; we have to look it up.
With the right table or computer we find z that corresponds to a probability p=.90 the integral of the unit normal from -z to z. Unfortunately these tables come in various flavors and we have to convert the probability to suit. Sometimes that's a one sided probability from zero to z. That would be an area aka probability of 0.45 from 0 to z (the "body") or a probability of 0.05 from z to infinity (the "tail"). Often the table is the integral of the bell from -infinity to positive z, so we'd have to find p=0.95 in that table. We know that the answer would be z=2 if our original p had been 95% so we expect a number a bit less than 2, a smaller number of standard deviations to include a bit less of the probability.
We find z=1.65 in the typical table has p=.95 from -infinity to z. So our 90% confidence interval is
in other words a margin of error of
dollars
That's around plus or minus 17 cents.
