3 divided by 4 in fraction form

Variance and standard deviation

kirza4 [7]

Answer: 8.3

Step-by-step explanation:

To find the variance, you want to find the mean of the data.

$\frac{3+3+8+1+9+6}{6} =5$

Now that we have the mean, we find the difference between each data point and the mean.

3-5=-2

8-5=3

1-5=-4

9-5=4

6-5=1

With the difference, you square each and find the average.

(-2)²=4

3²=9

(-4)²=16

4²=16

1²=1

$\frac{4+4+9+16+16+1}{6} =\frac{25}{3}$

The variance is 8.3.

3 0

3 years ago

Their is no point for brainly if you need to sign in I don't wanna be mean tho

Nesterboy [21]

but it helps with homework and learning how to do stuff you dont know how to do

3 0

3 years ago

Among freshman at a certain university, scores on the Math SAT followed the normal curve, with an average of 550 and an SD of 10

lina2011 [118]

Answer:

a) 6.68th percentile

b) 617.5 points

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 550, \sigma = 100$

a) A student who scored 400 on the Math SAT was at the ______ th percentile of the score distribution.

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{400 - 550}{100}$

$Z = -1.5$

$Z = -1.5$ has a pvalue of 0.0668

So this student is in the 6.68th percentile.

b) To be at the 75th percentile of the distribution, a student needed a score of about ______ points on the Math SAT.

He needs a score of X when Z has a pvalue of 0.75. So X when Z = 0.675.

$Z = \frac{X - \mu}{\sigma}$

$0.675 = \frac{X - 550}{100}$

$X - 550 = 0.675*100$

$X = 617.5$

6 0

3 years ago

Equation in slope-intercept form:

Jobisdone [24]

Answer:

y = -x + 3

Step-by-step explanation:

Find the slope using the formula [ y2-y1/x2-x1 ]. We can use the points (0, 3) and (3, 0) to solve.

0-3/3-0

-3/3

-1

From the graph, the y-intercept is (0, 3). Input all the data we know into the slope intercept form expression [ y = mx + b ].

y = -x + 3

Best of Luck!

5 0

3 years ago

7. Are the ordered pairs below an arithmetic sequence or geometric

DochEvi [55]

Answer:

8. Arithmetic Progression

9. $f(9) = 300$

Step-by-step explanation:

Given

$\{(1,55)\ (2, 45)\ (3, 35)\ (4, 25)\}$

Solving (8): Arithmetic or Geometric

We start by checking if it is arithmetic by checking for common difference (d).

$d = y_2 - y_1 = y_3 - y_2 = y_4 - y_3$

This gives:

$d = 45 - 55 = 35 - 45 = 25 - 35$

$d = -10 = -10 = -10$

$d=-10$

<em>Because the common difference is equal, then it is an arithmetic progression</em>

Solving (8):

$f(n) = f(1) + f(n-1)$

To find f(9), we substitute 9 for n

$f(9) = f(1) + f(9-1)$

$f(9) = f(1) + f(8)$

We need to solve for f(8); substitute 8 for n

$f(8) = f(1) + f(8 - 1)$

$f(8) = f(1) + f(7)$

We need to solve for f(7); substitute 7 for n

$f(7) = f(1) + f(7 - 1)$

$f(7) = f(1) + f(6)$

We need to solve for f(6); substitute 6 for n

$f(6) = f(1) + f(6 - 1)$

$f(6) = f(1) + f(5)$

We need to solve for f(5); substitute 6 for n

$f(5) = f(1) + f(5 - 1)$

$f(5) = f(1) + f(4)$

From the function, f(4) = 25 and f(1) = 55.

So:

$f(5)=55 + 25$

$f(5)=80$

$f(6) = f(1) + f(5)$

$f(6) = 55 + 80$

$f(6) = 135$

$f(7) = f(1) + f(6)$

$f(7) = 55 + 135$

$f(7) = 190$

$f(8) = f(1) + f(7)$

$f(8) = 55 + 190$

$f(8) = 245$

$f(9) = f(1) + f(8)$

$f(9) = 55 + 245$

$f(9) = 300$

8 0

3 years ago