Number 21 please help! Thank you!

Consider a value to be significantly low if its z score less than or equal to minus−2 or consider a value to be significantly hi

katrin2010 [14]

Answer:

Test scores of 10.2 or lower are significantly low.

Test scores of 31.4 or higher are significantly high.

Step-by-step explanation:

Problems of normally distributed samples can be 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:

$\mu = 20.8, \sigma = 5.3$

Identify the test scores that are significantly low or significantly high.

Significantly low

Z = -2 and lower.

So the significantly low scores are thoses values that are lower or equal than X when Z = -2. So

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

$-2 = \frac{X - 20.8}{5.3}$

$X - 20.8 = -2*5.3$

$X = 10.2$

Test scores of 10.2 or lower are significantly low.

Significantly high

Z = 2 and higher.

So the significantly high scores are thoses values that are higherr or equal than X when Z = 2. So

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

$2 = \frac{X - 20.8}{5.3}$

$X - 20.8 = 2*5.3$

$X = 31.4$

Test scores of 31.4 or higher are significantly high.

3 0

4 years ago

What is the solution of log2x + 6 8 = 3?

Fantom [35]

Answer:

Step-by-step explanation:

log(2x + 6) +8 = 3

Solve this log equation for x

First subtract 8 from both sides

log(2x+6)= -5

Now we convert it into exponential form

If log(x) = a then 10^a = x

log(2x+6)= -5 becomes

subtract 6 from both sides

Now we divide by 2 on both sides

x= -3 approximately

5 0

3 years ago

In the figure, a∥e , m∥n , and m∠3 = 108°. What is the m∠6 ? Enter your answer in the box.

maks197457 [2]

I believe that angle 6 is 108 because I drew to the best of my ability and I see that 3 and 6 are alternate interior angles.

3 0

3 years ago

A company finds it can produce 15 heaters for $ 4050â€‹, while producing 25 heaters costs $ 6550. Express theâ€‹ cost, y, as a l

amid [387]

Answer:

y=250x+300

Step-by-step explanation:

Let x be the number of heaters and y be the total cost.

We need to find the linear function for y in terms of x.

It is given that company can produce 15 heaters for $4050 and 25 heaters costs $ 6550.

It means the line passes through the points (15,4050) and (25,6550).

If a line passes through two points $(x_1,y_1)$ and $(x_2,y_2)$ , then the equation of line is

$y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)$

The equation of line is

$y-4050=\frac{6550-4050}{25-15}(x-15)$

$y-4050=\frac{2500}{10}(x-15)$

$y-4050=250(x-15)$

$y-4050=250x-3750$

Add 4050 on both sides.

$y-4050+4050=250x-3750+4050$

$y=250x+300$

Therefore, the required linear function is y=250x+300.

8 0

3 years ago

Help pls this is due today

artcher [175]

Answer:

2 x 1/3

Step-by-step explanation:

There are two bars of 1/3 so that's why it's 2 x 1/3

6 0

4 years ago

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