Answer:
y = -20
Step-by-step explanation:
Given that y varies directly with x it means changing x will also cause change in y
Mathematically it can be written as:
y∝x
Removing the proportionality symbol
y = kx
Given y=25 when x=5 Putting the values

Now

We have to find the value of y when x = -4
Putting x=-4

Hence,,
y = -20
Answer:
They would by able to go 4 miles.
Step-by-step explanation:
Answer:
4/10
Step-by-step explanation:
Answer:
6x^2 + 8x
Step-by-step explanation:
the 2 is on top of x, so its squared
Answer:
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 40.6 - 0.2 = 40.4 words per minute.
The upper end of the interval is the sample mean added to M. So it is 40.6 + 0.2 = 40.8 words per minute.
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.