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
Answer:
Step-by-step explanation:
Let's solve 2x^2 = -X^2 - 5x - 1. Consolidate all terms on the left side and write 0 on the right side:
3x^2 + 5x + 1 = 0. This is a quadratic equation. Let's solve it for x using the quadratic formula:
a = 3, b = 5, c = 1, and so the discriminant is b^2 - 4ac = 5^2 - 4(3)(1) = 13. Because the discriminant is positive, we know that there are two distinct, real roots; the graphs of y = 2x^2 and y = x^2 - 5x - 1 intersect in two places whose x-coordinates are the real roots mentioned above.
Answer A is not correct as stated, but would be correct if we were to replace "the y-coordinates" with "the x-coordinates."
Answer C would be correct if and only if we write y = x^2 - 5x - 1.
Answer:
2/3
Step-by-step explanation:
fraction of book already read = 1/3
fraction which represents whole book = 1 = 3/3
fraction of remaining book = fraction of whole book - fraction of book already read
= 1 - 1/3
= 3/3 - 1/3
= (3-1) /3
= 2/3
In the given question, there are two vital information's give. Firstly 8 ears of corn and 1 cantaloupe cost $2.37. On the other hand 6 ears of corn and 3 cantaloupes cost $3.51.
Let us assume the cost of 1 corn = X
Let us assume the cost of 1 cantaloupe = Y
Then
8X + Y = 2.37
Y = 2.37 - 8X
And
6X + 3Y = 3.51
Now we replace the value of Y we found from the first equation
Then
6X + 3(2.37 - 8X) = 3.51
6X - 24X + 7.11 = 3.51
-18X = 3.51 - 7.11
-18X = -3.6
X = 3.6/18
= 0.20
So $0.20 is the value of 1 corn. Then the value of a cantaloupe
Y = 2.37 - 8X
= 2.37 - (8 * 0.20)
= 2.37 - 1.6
= 0.77
So cost of a cantaloupe is $0.77
