Answer:
The probability the he or she will answer correctly is 1.5%
Step-by-step explanation:
In all, there are 18 problems. In this question, the order of which the problems are sorted for the quiz makes no difference. For example, if the question A of the quiz is P1 and question B P2, and question A P2 and question B P1, it is the same thing.
There are 18 problems and 9 are going to be selected. So, there is going to be a combination of 9 elements from a set of 18 elements.
A combination of n elements from a set of m objects has the following formula:
In this question, m = 18, n = 9. So the total number of possibilities is:
Now we have to calculate the number of desired outcomes. This number is a combination of 9 elements from a set of 13 elements(13 is the number of problems that the student has figured out how to do).
Now, m = 13, n = 9. The number of desired possibilities is:
The probability is the number of desired possibilities divided by the number of total possibilities. So
The probability the he or she will answer correctly is 1.5%
1.) X=-2
2.) 2x-y+4=0
Hope this helps! :))
Answer: a) about 450
Step-by-step explanation:
50 multiplied by 9 is 450 and its asking for an approximate so it would be anything near 450
Answer:
<u>Given</u>
and
<em>See the graphs attached</em>
To draw the graphs follow the rules we described in the previous questions.
- 1. Identify x-intercept and y-intercept and connect them to have the line.
- 2. Shade the region above or below the line for the inequality.
We see the only difference the expressions have is the equation or inequality symbols.
- Equation symbol means the graph of the equation is a line.
- Inequality symbol means the graph of this is a region above the same line, in our case the line is not a part of the covered region because it is "<".
We can state that the inequality excludes the line and includes only the region above the same line.
Answer:
Let X the random variable that represent the number of children per fammili of a population, and for this case we know the following info:
Where 
and 
We select a sample of n =64 >30 and we can apply the central limit theorem. From the central limit theorem we know that the distribution for the sample mean 
is given by:
And for this case the standard error would be:
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 central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".
Solution to the problem
Let X the random variable that represent the number of children per fammili of a population, and for this case we know the following info:
Where and
We select a sample of n =64 >30 and we can apply the central limit theorem. From the central limit theorem we know that the distribution for the sample mean is given by:
And for this case the standard error would be:
