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3 years ago

What value has a z-score of -0.67, if the mean is 18 and the standard deviation is 1.68?

1 answer:

7 0

The data point is 1.6 standard deviations above the mean.
Step-by-step explanation:
Z-score
It is the number of standard deviations from the mean that a data point is. It's a measure of how many standard deviations below or above the population mean a raw score is.
A Z-score is also known as a standard score and it can be placed on a normal distribution curve.
As in this case the Z-score is +1.6, so it means the data point is 1.6 standard deviations above the mean. Hope this helps I am kinda knew to this so I hope I helped you

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What is the slope of a line that passes through the points (–3, 2) and (–6, 5)?

lilavasa [31]

Answer:

-1

Step-by-step explanation:

just do y2-y1 over x2-x1.

8 0

3 years ago

Which of the following is NOT true?

worty [1.4K]

A trapezoid is a rectangle.

8 0

3 years ago

Read 2 more answers

Which classification describes AMNO with vertices M(2, -3), N(3, 1), and<br> 0(-3, 1)?

Sonja [21]

Answer:

Option D

Step-by-step explanation:

32). Given vertices of the triangle are M(2, -3), N(3, 1) and O(-3. 1).

Distance between two points $(x_1,y_1)$ and $(x_2,y_2)$ is given by the expression,

Distance = $\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

Distance between M(2, -3) and N(3, 1) will be,

MN = $\sqrt{(3-2)^2+(1+3)^2}$

= $\sqrt{1+16}$

= $\sqrt{17}$

Distance between M(2, -3) and O(-3, 1),

MO = $\sqrt{(2+3)^2+(-3-1)^2}$

= $\sqrt{25+16}$

= $\sqrt{41}$

Distance between N(3, 1) and O(-3, 1),

NO = $\sqrt{(3+3)^2+(1-1)^2}$

= 6

Condition for right triangle,

c² = a² + b² [Here c is the longest side of the triangle]

By this property,

MO² = MN² + NO²

$(\sqrt{41})^2=(\sqrt{17})^2+6^2$

41 = 17 + 36

41 = 51

False.

Therefore, given triangle is not a right triangle.

Since, length of all sides are not equal, given triangle will be a scalene triangle.

Option D is the correct option.

5 0

3 years ago

Given: cos α = 4/5, sin β= 4/5, and α and β are both in quadrant 1. find sin (α+β)

mezya [45]

We have the formula (sin x)^2 + (cos x)^2 = 1;
Then, sin α = $\sqrt{1- ( \frac{4}{5}) ^{2} } = \frac{3}{5} ;$
cos β = $\sqrt{1- ( \frac{4}{5}) ^{2} } = \frac{3}{5} ;$
We apply the formula sin ( α + β ) = sin α x cos β + sin β x cos α = (3/5)x(4/5) + (4/5)x(3/5) = 12/25 + 12/25 = 24/25;

8 0

4 years ago

The frequency distributions of two data sets are shown in the dot plots below.

fredd [130]

Answer:

1st, 4th and 6th statements are true.

Step-by-step explanation:

We have been given two dot-plots and we are asked to select all the true statements about given dot plots.

Let us write all the data points of both dot plots.

Data set 1:

1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 7.

Data set 2:

1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4.

1. The mean of data set 1 is greater than the mean of data set 2.

Let us find mean of both data sets.

$\text{Mean of data set 1}=\frac{1+1+1+1+1+2+2+2+2+2+2+2+2+3+3+3+4+4+7}{19}$

$\text{Mean of data set 1}=\frac{45}{19}$

$\text{Mean of data set 1}=2.3684\approx 2.37$

$\text{Mean of data set 2}=\frac{1+1+1+1+1+2+2+2+2+2+2+2+2+3+3+3+4+4}{18}$

$\text{Mean of data set 2}=\frac{38}{18}$

$\text{Mean of data set 2}=2.11$

We can see that mean of data set 1 is greater than mean of data set 2, therefore, 1st statement is true.

2. The mean of data set 1 is equal to the mean of data set 2.

Since mean of data set 1 is greater than mean of data set 2, therefore, 2nd statement is false.

3. The median of data set 1 is greater than the median of data set 2.

Since data set 1 has 19 data points, so median of data set 1 will be value of 10th data set, that is 2.

Our data set 2 has 18 data points, so median of data set 2 will be the average of 9th and 10th data points.

$\text{Median of data set 2}=\frac{2+2}{2}$

$\text{Median of data set 2}=\frac{4}{2}=2$

Since median of data set 2 is also 2, therefore, 3rd statement is not true.

4. The median of data set 1 is equal to the median of data set 2.

Since both data set's median is 2, therefore, 4th statement is true.

5. The standard deviation of data set 1 is smaller than the standard deviation of data set 2.

Using online SD calculator we get SD of data set 1 is 1.422 and SD of data set 2 is 0.936. Since 1.422 is greater than 0.936, therefore, 5th statement is false.

6. The data sets have the same interquartile range.

$Q_1\text{ of data set 1}=1$