First multiply (4x5)
Then find 2 cubed = 2x2x2= 8
Then divide 20 by 2= 20/2=10
Then 10-8= 2
10-4=6 im not s. sure rhia ia correct. What grade are you in?
Answer: The radius is
r
=
3
.
Explanation:
If the point
(
−
3
,
2
)
belongs to the circle
(
x
+
3
)
2
+
(
y
+
1
)
2
−
r
2
=
0
then its coordinates must verify that equation. That is, if we substitute in the equation of the circle
x
by
−
3
and
y
by
2
we must obtain a true equality. Then, it is enough to clear
r
of that equation:
(
−
3
+
3
)
2
+
(
2
+
1
)
2
−
r
2
=
0
⇒
9
−
r
2
=
0
,
then:
r
=
√
9
=
3
.
(Remember
r
is a distance, then it's always a positive number).
Step-by-step explanation:
Given a = {1, 2, 3, 4, 5, 6, 7, 8, 9} and b = {2, 4, 6, 8} what is AUB?
cestrela7 [59]
<span>AUB is the union of sets A and B.
It is a set that contains every element of set A and every element of set B.
Write a set that has all the numbers in both sets A and B. Be sure to write each number only once even if the number appears in both sets A and B.
</span>
First, let’s break this down. What exactly are we looking at here? Well, Daisy measured the heights of 20 plants (in cm). The table, under Frequency, shows the # of plants that fit within a certain height range, shown on the left under Height of Plants (h).
Now, it says to take the midpoints of each group to figure out an estimate of the mean height. To find the mean, you add up all the totals and divide it by the # of items. So, let’s go through each row.
Midpoint of 0-10 is 5, and Frequency is 1, so that gives us 5.
Midpoint of 10-20 is 15, Frequency is 4, and 15x4=60.
We continue this with the other rows by finding the midpoint & multiplying the midpoint by the frequency (if the frequency is greater than 1). This gives us the numbers:
175 (25x7)
70 (35x2)
135 (45x3)
165 (55x3)
Now, we add these all together.
5+60+175+70+135+165=610
Finally, we divide 610 by the # of items (remember, there are 20 plants so we divide by 20) and 610/20 is 30.5.
FINAL ANSWER:
Thus, if I calculated correctly (which I hope I did lol), our estimate for the mean height of a plant is 30.5 cm!