On a bicycle trail, the city is painting arrows like the one shown below:

This box plot shows information about the marks scored in a test.

aliina [53]

Since 120 students gained less than 70, and 70 is the upper quartile, 120 people are in the 75% of all the students so we need to find the total number of students.
we need to multiply 0.75 (75%) by something to get 120. which is 160 (the total number of all students).
and since 48 is the median score, find 50% of 160 which is 80!
hope this helps :)

4 0

2 years ago

Explain why this matrix equation has no solution: A 11 17 −8 13 = 0 0 0 0.

qwelly [4]

The matrix equation has no solution because the same matrix of equal magnitude and opposite in nature is been added to it.

Given to us

A + [11 17 -8 13] = [0 0 0 0]

<h3>What is the value of matrix A?</h3>

We know that the given matrix will give values as zero if the same matrix is been deducted from it, therefore,

A + [11 17 -8 13] = [0 0 0 0]

A = [0 0 0 0] - [11 17 -8 13]

A = [-11 -17 +8 -13]

Thus, the matrix is equal to [-11 -17 +8 -13].

<h3>why this matrix equation has no solution?</h3>

The matrix equation has no solution because the same matrix of equal magnitude and opposite in nature is been added to it, therefore, [11 17 -8 13] is been added to it.

Thus, the sum of the two matrices has no solution.

Learn more about Matrices:

brainly.com/question/11367104

5 0

2 years ago

Health insurers are beginning to offer telemedicine services online that replace the common office visit. A company provides a v

Veronika [31]

Answer:

$\text {CI} = (60.54, \: 81.46)\\\\$

Therefore, we are 95% confident that actual mean savings for a televisit to the doctor is within the interval of ($60.54 to $81.46)

Step-by-step explanation:

Let us find out the mean savings for a televisit to the doctor from the given data.

Using Excel,

=AVERAGE(number1, number2,....)

The mean is found to be

$\bar{x} = \$71$

Let us find out the standard deviation of savings for a televisit to the doctor from the given data.

Using Excel,

=STDEV(number1, number2,....)

The standard deviation is found to be

$s = \$ 22.35$

The confidence interval is given by

$\text {confidence interval} = \bar{x} \pm MoE\\\\$

Where the margin of error is given by

$$ MoE = t_{\alpha/2}(\frac{s}{\sqrt{n} } ) $ \\\\$

Where n is the sample of 20 online doctor visits, s is the sample standard deviation and $t_{\alpha/2}$ is the t-score corresponding to a 95% confidence level.