Answer:
Where 
and 
Since the distribution for X is normal then the distribution for the sample mean is also normal and given by:
So then is appropiate use the normal distribution to find the probabilities for 
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean". The letter 
is used to denote the cumulative area for a b quantile on the normal standard distribution, or in other words: 
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where and
Since the distribution for X is normal then the distribution for the sample mean is also normal and given by:
So then is appropiate use the normal distribution to find the probabilities for
Solve for x:8 (13 - 6 x) + 6 x = 0
8 (13 - 6 x) = 104 - 48 x:
6 x + 104 - 48 x = 0
6 x - 48 x = -42 x:
-42 x + 104 = 0
Subtract 104 from both sides:
(104 - 104) - 42 x = -104
104 - 104 = 0:
-42 x = -104
Divide both sides of -42 x = -104 by -42:
(-42 x)/(-42) = -104/(-42)
(-42)/(-42) = 1:
x = -104/(-42)
The gcd of 104 and -42 is 2, so -104/(-42) = -(2×52)/(2 (-21)) = 2/2×(-52)/(-21) = (-52)/(-21):
x = (-52)/-21
Multiply numerator and denominator of (-52)/(-21) by -1:
Answer: x = 52/21
This is easy 4x+12 the answer
Answer: 4×15= 60
Step-by-step explanation:
60 is 15 times as many as 4. This means that 15 is multiplied by 4 to get 60. This will be :
4×15= 60.
The other options such as 60÷15=4, 15+4= 60, 60÷4=15 and 60-15= 4 doesn't explain the question given. 60-15 is not 4 likewise 15+4 isn't 60. For the other options, the question isn't talking about division but multiplication.
