25 because you have to multiply 5✖️5 which equals 25. 5 is the 5 layers and the other 5 for the 5 rows.
Find the z-scores for the two scores in the given interval.

For the score x =391,

.
For the score x = 486,

Now you want the area (proportion of data) under the normal distribution from z = -1 to z = 0. The Empirical Rule says that 68% of the data falls between z = -1 to z = 1. But the curve is symmetrical around the vertical axis at z = 0, so the answer you want is HALF of 68%.
Y = 25 times x
or you could write it as
y=25x
•
hope this helps!
Answer:
They will be 170 miles apart at 10 AM
Step-by-step explanation:
Nancy has 15´ of head start which is 1/4 hr.
NHD = 20*(1/4) = 5 miles is her head start
Mark leaves at 7.15hs = starting point
Marks stop at when they are 170 miles apart = t
------------------------------
t = the time they are 170 miles apart
d= distance in miles Nancy travels in time t
170 - (d+5) = distance in miles Mark travels in time t
------------------------------
Nancy's equation:
(1) d = 20t
Mark's equation:
(2) 170 - (d+5) = 40t
---------------------------
(2) 170-d-5=40t
(2) d+40t=165
Substitute (1) into (2)
(2) 20t+40t=165
(2) 60t=165
(2) t=2.75
7:15 AM + 2.75 hrs (2:45hs) = 10 AM
They are 170 miles apart at 10 AM
check:
(1) d=20t
(1) d=20*2.75
(1) d=
55
---------------
(2) 170 - (d+5) = 40t
(2) 170 - (d+5) = 40*2.75
(2) 170 - d-5 = 110
(2) d=55
If given a line in the slope-intercept form
y=mx+b
m is the slope and b is they y-intercept