A 2-pack of notebooks costs $3.00. What is the unit price? per notebook

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

A fountain is made up of two semicircles and a quarter circle. Find the perimeter of the fountain. Round answers to nearest tent

AlexFokin [52]

Answer:

39.275

Step-by-step explanation:

the diameter of the semicircle is 10

A semicircle is half a circle, and a quarter circle is 1/4 of a circle.

Perimeter of a semicircle is ¶d/2

= 3.142 x 10/2 = 3.142 x 5 = 15.71

For 2 semicircles that will be 15.71 x 2 = 31.42

For the quarter circle, perimeter is ¶d/4 = 3.142 x 10/4 = 3.142 x 2.5 = 7.855

Total perimeter = 31.42 + 7.855 = 39.275

5 0

3 years ago

1.172 as a percentage?

hodyreva [135]

Answer: 117.2%

Step-by-step explanation:

Multiply both numerator and denominator by 100. We do this to find an equivalent fraction having 100 as the denominator.

Multiply both numerator and denominator by 100. We do this to find an equivalent fraction having 100 as the denominator.

= (1.172 × 100) × 1/100=117.2/100

Write in percentage notation: 117.2%

8 0

3 years ago

Read 2 more answers

A regular pentagon with a perimeter of 21 inches is dilated by a scale factor of

levacccp [35]

<h3>Answer: 35 inches</h3>

Each side of the pentagon is multiplied by 5/3 to get the length of each new side, so the perimeter is multiplied by 5/3 to get the new perimeter.

New perimeter = (scale factor)*(old perimeter)

New perimeter = (5/3)*(old perimeter)

New Perimeter = (5/3)*(21)

New Perimeter = (5/3)*(21/1)

New Perimeter = (5*21)/(3*1)

New Perimeter = 105/3

New Perimeter = 35 inches

5 0

3 years ago

Read 2 more answers

a circular frame that is 3-inches wide surrounds the mirror what I the combined area in square inches of the circular mirror and

Tcecarenko [31]

Assuming the frame is a perfect circle
and 3 inches wide indicates the diameter

area of a circle=pi times radius^2

diameter=2 times radius
radius=1/2 diameter
diameter=3
radius=1/2 times 3
radius=3/2=1.5

area=pi times 1.5^2=2.25
pi is aprox 3.14 so
2.25 times 3.14=7.065 square inches

the answer is 2.25π square inches or 7.065 square inches

3 0

3 years ago