Use multiplication to solve the following problems.

A data set with a mean of 34 and a standard deviation of 2.5 is normally distributed

tresset_1 [31]

Answer:

a) $z= \frac{34-34}{2.5}= 0$

$z= \frac{39-34}{2.5}= 2$

And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %

b) $P(X$

$z= \frac{31.5-34}{2.5}= -1$

So one deviation below the mean we have: (100-68)/2 = 16%

c) $z= \frac{29-34}{2.5}= -2$

$z= \frac{36.5-34}{2.5}= 1$

For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%

Step-by-step explanation:

For this case we have a random variable with the following parameters:

$X \sim N(\mu = 34, \sigma=2.5)$

From the empirical rule we know that within one deviation from the mean we have 68% of the values, within two deviations we have 95% and within 3 deviations we have 99.7% of the data.

We want to find the following probability:

$P(34 < X$

We can find the number of deviation from the mean with the z score formula:

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

And replacing we got

$z= \frac{34-34}{2.5}= 0$

$z= \frac{39-34}{2.5}= 2$

And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %

For the second case:

$P(X$

$z= \frac{31.5-34}{2.5}= -1$

So one deviation below the mean we have: (100-68)/2 = 16%

For the third case:

$P(29 < X$

And replacing we got:

$z= \frac{29-34}{2.5}= -2$

$z= \frac{36.5-34}{2.5}= 1$

For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%

7 0

3 years ago

The laptop was marked down from $895 to $720.

Vedmedyk [2.9K]

Answer:

Wdym?

Step-by-step explanation:

Im confused

4 0

2 years ago

What is the equation of this graphed line?

Eva8 [605]

Answer:

y = -9/8x + 7

Step-by-step explanation:

Slope-intercept form is:

y = mx + b

Points given:

(0, 7) and (8, -2)

y-intercept is

b = 7 as per the first point

And the slope is:

m = (-2 - 7)/(8 - 0) = -9/8

So the line is:

y = -9/8x + 7

6 0

3 years ago

Read 2 more answers

Eva took a taxi from her house to the airport. The taxi company charged a pic of feet of 3 dollars and 20 cents, plus 3 dollars

svetoff [14.1K]

Answer:

3x + 3.20 =33.20

Step-by-step explanation:

4 0

2 years ago

You buy a total of 25 burgers and tacos for $67.50. The burgers cost $3.50 each and the tacos cost $2.25 each. Find the number o

Ahat [919]

Answer: you bought 9 burgers and 16 tacos

Step-by-step explanation:

Let x represent the number of burgers that you bought.

Let y represent the number of tacos that you bought.

You buy a total of 25 burgers and tacos. It means that

x + y = 25

The burgers cost $3.50 each and the tacos cost $2.25 each. The total cost of the burgers and tacos that you bought is $67.50. It means that

3.5x + 2.25y = 67.5- - - - - - - - - - - - 1

Substituting x = 25 - y into 1, it becomes

3.5(25 - y) + 2.25y = 67.5

87.5 - 3.5y + 2.25y = 67.5

- 3.5y + 2.25y = 67.5 - 87.5

- 1.25y = - 20

y = - 20/ - 1.25

y = 16

x = 25 - y = 25 - 16

x = 9

5 0

3 years ago