The answer is 30. 360/12.
The only way to solve if it is equal to something
assuming that the teacher wanted you to make it equal to zero do
0=-3x^2-21x-54
remember if we can do
xy=0 then assume x and y=0
so factor
0=-3x^2-21x-54
undistribute the -3
0=-3(x^2+7x+18)
remember 0 times anything=0 so
x^2+7x+18 must equal zero
use quadratice formula which is
if you have
ax^2+bx+c=0 then
x=

x^2+7x+18
a=1
b=7
c=18
x=

x=

x=

i=√-1
x=

the zerose would be
x=

or
Answer: Option (c) is correct.
68% of the data points lie between 10 and 18.
Step-by-step explanation: Given : a normal distribution with a standard deviation of 4 and a mean of 14
We have to choose the sentence that correctly describes a data set that follows a normal distribution with a standard deviation of 4 and a mean of 14.
Since, given 68% data.
We know mean of data lies in middle.
And standard deviation is distribute equally about the mean that is 50% of values less than the mean and 50% greater than the mean.
So, 68% of data lies
mean - standard deviation = 14 - 4 = 10
mean + standard deviation = 14 + 4 = 18
So, 68% of the data points lie between 10 and 18.
The answer is 0.15290519877