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3 years ago

How do I solve a probability question?

1 answer:

3 0

Solving probability is finding the likely hood of an event. So for example if you have 4 red circles and 3 yellow and you were trying to find the probability of picking yellow, you would add all of the blocks together. After you would put the problem into a fraction; with 3(the amount we are given) on top and 7(the total) on the bottom. I hope that helps but if it’s a more specific question, let me know!

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How many 3/8s are in 6

dlinn [17]

Answer:

Step-by-step explanation:

6 divided by 3/8=6*8/3=48/3=16

5 0

3 years ago

A student wanted to construct a 95% confidence interval for the average age of students in her statistics class. She randomly se

Darina [25.2K]

Answer: (17.42, 20.78)

Step-by-step explanation:

As per given , we have

Sample size : n= 9

$\overline{x}=19.1$ years

Population standard deviation is not given , so it follows t-distribution.

Sample standard deviation : s= 1.5 years

Confidence level : 99% or 0.99

Significance level : $\alpha= 1-0.99=0.01$

Degree of freedom : df= 8 (∵df =n-1)

Critical value : $t_c=t_{(\alpha/2,\ df)}=t_{0.005,\ 8}= 3.355$

The 99% confidence interval for the population mean would be :-

$\overline{x}\pm t_c\dfrac{s}{\sqrt{n}}$

$19.1\pm (3.355)\dfrac{1.5}{\sqrt{ 9}}\\\\=19.1\pm1.6775\\\\=(19.1-1.6775,\ 19.1+1.6775)\\\\=(17.4225,\ 20.7775)\approx(17.42,\ 20.78)$

Hence, the 99% confidence interval for the population mean is (17.42, 20.78) .

7 0

3 years ago

Find the median of the following set of data. Round your answer to the nearest hundredth, if necessary.

Usimov [2.4K]

The correct answer is 35.2 because when you arrange them in order from least to greatest, the middle is 35.2

8 0

3 years ago

Function (A or B) has the greater initial value because the initial value for function A is _ and the initial value for Function

Volgvan

Answer:

Function B has the greater initial value because the initial value for function A is 4 and the initial value for Function B is 5

Step-by-step explanation:

<em>The initial value of a function is the output value of the function when the input value is 0</em>

Initial value of A is y=4 at x=0,

and

initial value of B is y=0*6+5= 5 at x=0

Function B has the greater initial value because the initial value for function A is 4 and the initial value for Function B is 5

5 0

3 years ago

The system of equations may have a unique solution, an infinite number of solutions, or no solution. Use matrices to find the ge

Leno4ka [110]

Answer:

Infinite number of solutions.

Step-by-step explanation:

We are given system of equations

$5x+4y+5z=-1$

$x+y+2z=1$

$2x+y-z=-3$

Firs we find determinant of system of equations

Let a matrix A= $\left[\begin{array}{ccc}5&4&5\\1&1&2\\2&1&-1\end{array}\right]$ and B= $\left[\begin{array}{ccc}-1\\1\\-3\end{array}\right]$

$\mid A\mid=\begin{vmatrix}5&4&5\\1&1&2\\2&1&-1\end{vmatrix}$

$\mid A\mid=5(-1-2)-4(-1-4)+5(1-2)=-15+20-5=0$

Determinant of given system of equation is zero therefore, the general solution of system of equation is many solution or no solution.

We are finding rank of matrix

Apply $R_1\rightarrow R_1-4R_2$ and $R_3\rightarrow R_3-2R_2$

$\left[\begin{array}{ccc}1&0&1\\1&1&2\\0&-1&-3\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\1\\-5\end{array}\right]$

Apply $R_2\rightarrow R_2-R_1$

$\left[\begin{array}{ccc}1&0&1\\0&1&1\\0&-1&-3\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\6\\-5\end{array}\right]$

Apply $R_3\rightarrow R_3+R_2$

$\left[\begin{array}{ccc}1&0&1\\0&1&1\\0&0&-2\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\6\\1\end{array}\right]$

Apply $R_3\rightarrow- \frac{1}{2}$ and $R_2\rightarrow R_2-R_3$

$\left[\begin{array}{ccc}1&0&1\\0&1&0\\0&0&1\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\\frac{13}{2}\\-\frac{1}{2}\end{array}\right]$

Apply $R_1\rightarrow R_1-R_3$

$\left[\begin{array}{ccc}1&0&0\\0&1&0\\0&0&1\end{array}\right]$ : $\left[\begin{array}{ccc}-\frac{9}{2}\\\frac{13}{2}\\-\frac{1}{2}\end{array}\right]$

Rank of matrix A and B are equal.Therefore, matrix A has infinite number of solutions.

Therefore, rank of matrix is equal to rank of B.

4 0

3 years ago