The histogram shows the number of cell phone calls received by Medera, a middle school student, one Saturday from 10 a.m. to 10 p.m.


A histogram titled Cell Phone Calls has time of day on the x-axis and number of calls on the y-axis. From 10 to 12 pm there were 2 calls; from 12 to 2 pm there were 8 calls; from 2 to 4 pm there were 0 calls; from 4 to 6 pm there were 10 calls; from 6 to 8 pm there were 4 calls; from 8 to 10 pm there were 2 calls.

Which statement most reasonably explains the hours when zero calls were received?
Medera turned the phone off while playing in a soccer game.
Medera’s phone can only receive 22 calls a day.
Medera only receives calls in clusters.
Medera lost her phone for two hours.

Answer:

a) 0.005% probability of a pregnancy lasting 308 days or longer

b) The pregnancy length that separates premature babies from those who are not premature is 229 days.

Step-by-step explanation:

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

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

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 question, we have that:

[tex]\mu = 250, \sigma = 15[/tex]

a. Find the probability of a pregnancy lasting 308 days or longer?

This is 1 subtracted by the pvalue of Z when X = 308. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{308 - 250}{15}[/tex]

[tex]Z = 3.87[/tex]

[tex]Z = 3.87[/tex] has a pvalue of 0.99995

1 - 0.99995 - 0.00005

0.005% probability of a pregnancy lasting 308 days or longer

b. If we stipulate that a baby is premature if the length of the pregnancy is in the lowest 8% (8th percentile), find the length that separates premature babies from those who are not premature.

The 8th percentile is X when Z has a pvalue of 0.08. So it is X when Z = -1.405.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.405 = \frac{X - 250}{15}[/tex]

[tex]X - 250 = -1.405*15[/tex]

[tex]X = -1.405*15 + 250[/tex]

[tex]X = 229[/tex]

The pregnancy length that separates premature babies from those who are not premature is 229 days.

Answer:

The probability that all compressors are off = P(A ∩ B') = 0.18

Step-by-step explanation:

Event A is denoted to reciprocal compressor (R) that is always off.

Event B is denoted that at least one of the screw type of compressor is always on.

P(A) = Probability that the reciprocal compressor is off.

P(A') = Probability that the reciprocal compressor is on.

P(B) = Probability that at least one of the screw type of compressor is on.

P(B') = Probability that at least one of the screw type of compressor is off.

P(A ∩ B) = 45% = 0.45

P(A ∪ B) = 93% = 0.93

P(U) = P(A ∪ B) + P(A' ∩ B')

1 = 0.93 + P(A' ∩ B')

P(A' ∩ B') = 1 - 0.93 = 0.07

The probability that all compressors are off is given as P(A ∩ B')

P(A) = P(A n B') + P(A n B)

P(B) = P(A n B) + P(A' n B)

The question asks us to assume that all outcomes in event B are equally likely.

The possible outcomes in event B include

- The two compressors are on

- First compressor is on, second compressor is off

- Second compressor is on, first compressor is off

- both compressors are off

Since all the outcomes are equally likely, the probability that at least one of the two compressors is on = (3/4) = 0.75 = P(B)

P(B) = P(A n B) + P(A' n B)

0.75 = 0.45 + P(A' n B)

P(A' n B) = 0.75 - 0.45 = 0.30

P(A ∪ B) = P(A ∩ B') + P(A' ∩ B) + P(A ∩ B)

0.93 = P(A ∩ B') + 0.30 + 0.45

P(A ∩ B') = 0.93 - 0.30 - 0.45 = 0.18

Hope this Helps!!!

Answer:

Step-by-step explanation:

If Collete planted a row of lettuce, that means their coordinates must have the same vertical coordinate, or the same horizontal coordinate. Another important characteristic is that between those points, there must have 8 units of separation, because it's an 8-foot row.

Only the first choice offers these characteristic to properly represent the row of plants with 8 feet distance between the first and the last plant.

Therefore, the answer is (-4,-1) and (-4,7)

Answer:

(-4, -1) and (-4, 7)

Step-by-step explanation:

I did the quiz

Answer:3.3

Step-by-step explanation:

Circumference=8

Φ=288

π=3.14

Radius=r

Circumference=2 x π x r

8=2 x 3.14 x r

8=6.28 x r

Divide both sides by 6.28

8/6.28=(6.28 x r) /6.28

1.3=r

r=1.3

Length of arc =Φ/360 x 2 x π x r

Length of arc =288/360 x 3.14 x 1.3

Length of arc =0.8 x 3.14 x 1.3

Length of arc =3.3

Answer:32/5

Step-by-step explanation: did it in khan

Answer:

a) 4 hours

b) 11 am

Step-by-step explanation:

So say the number of hours is x

a) 72 + 6x = 96

6x = 24

x = 4

b) 7am + 4 hours = 11am

Answer:

c

Step-by-step explanation:

Answer:

it's D

Step-by-step explanation:

The number never goes over 0 so there is no need to put anything above 0

Answer:

  1024 pi

Step-by-step explanation:

The area formula is ...

  A = πr^2

So, the radius is ...

  r = √(A/π)

For the given area, the radius of the cylinder is ...

  r = √(64π/π) = 8 . . . . cm

The height is said to be twice this value, so is 16 cm.

__

The volume of the cylinder is found from ...

  V = Bh

where B is the base area and h is the height. Our cylinder has a volume of ...

  V = (64π cm^2)(16 cm) = 1024π cm^3

Answer:

(0,1)

Step-by-step explanation:

i got it right

Answer:

r = 5.97 cm

Step-by-step explanation:

The area of the sector is given by the following equation:

[tex]A = r*S = 2\pi*r^{2}*\frac{58}{360}[/tex]

Where:

r: is the radius

A: is the area

The radius is:

[tex]r = \sqrt{\frac{A}{2*\pi*58/360}} = \sqrt{\frac{36.07 cm^{2}}{2*\pi*58/360}} = 5.97 cm[/tex]

Therefore, the radius of Circle M is 5.97 cm.

I hope it helps you!

Answer: Equilateral, isosceles and scalene.

Step-by-step explanation:

Answer:

(6,4)

Step-by-step explanation:

I just did quick math in my head.

Answer:A

Step-by-step explanation:

h=85 f=36

Since it is a right angled triangle we can apply Pythagoras principle to get g

g=√(h^2 - f^2)

g=√(85^2 - 36^2)

g=√(85x85 - 36x36)

g=√(7225 - 1296)

g=√(5929)

g=77

Answer:

a = ln (2b)

Step-by-step explanation:

2e^a =4b

Divide each side by 2

2/2 e^a =4/2b

e^a = 2b

Take the natural log of each side

ln(e^a) = ln(2b)

a = ln (2b)

Answer:

1310720

Step-by-step explanation:

Find out the frist part "4 to the square root of 81"  262144

then times it by 5

to get 1310720

Answer: x= 5

Step-by-step explanation: Lets solve by completing the square.

You first need to get -15 by itself.

x^2-8x=15   Now you need to complete the square my finding a perfect constant that will go with x^2-8x, then add it to the other side containing -15 to balance the equation out.

-8x/2= -4^2=16 This will be the perfect square.

x^2-8x+16 = -15 + 16

(x-4)^2 = 1 factor into a binomial, then use the square root on both sides.

√ x-4 ^ 2 = √ 1

x-4 = 1

x=5

Answer:

Answer: Option B. 16^4 is the correct answer.

Step-by-step explanation:

Answer:

Step-by-step explanation:

b

Answer:

[tex]0.60 - 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.570[/tex]

[tex]0.60 + 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.630[/tex]

The 95% confidence interval for the true proportion would be given by (0.570;0.630) .

And if we convert this into % we got (57.0%, 63.0%)

Step-by-step explanation:

The information given we have the following info given:

[tex] n = 1019[/tex] represent the sampel size

[tex] \hat p=0.6[/tex] represent the sample proportion of interest

The confidence level is 95%, our significance level would be given by [tex]\alpha=1-0.95=0.05[/tex] and [tex]\alpha/2 =0.025[/tex]. And the critical value would be given by:

[tex]z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96[/tex]

The confidence interval for the mean is given by the following formula:  

[tex]\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}[/tex]

Replacing the info given we got:

[tex]0.60 - 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.570[/tex]

[tex]0.60 + 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.630[/tex]

The 95% confidence interval for the true proportion would be given by (0.570;0.630) .

And if we convert this into % we got (57.0%, 63.0%)

Answer:

y=a

Step-by-step explanation:

Answer:

D

If you put the equation into a calculator, it will show a graph of it.

Answer:

Rectangular prism          

Step-by-step explanation:

4 points below the origin

Answer:

255.50

Step-by-step explanation:

If each day the number is doubled, then all you must do is keep on doubling to the ninth day and then add it all together

Answer:

Option B

Step-by-step explanation:

The figures are made out of squares.

[tex]\text {Formula for area of a square: } A =s^2\\s-\text {Length of side.}[/tex]

Square 1 (the gray square):

The side measure is 4 cm.

[tex]A = 4^2 = 16cm^2[/tex]

Square 2 (white square):

The side measure is 2 cm.

[tex]A=2^2=4cm^2[/tex]

Subtract the area of the white square from the gray square to get the area of the shaded region:

[tex]16 - 4 =12[/tex]

The shaded region is [tex]12cm^2[/tex].

Option B should be the correct answer.

Brainilest Appreciated!

Answer:3hk - 12.4h

Step-by-step explanation:

h(3k-12.4)

h x 3k - h x 12.4

3hk - 12.4h

Answer: 2r(0)/3.

Step-by-step explanation:

So, we are given one Important data or o or parameter in the question above and that is the function of the form which is given below(that is);

S(r) = (r0 - r) ar^2 -----------------------------(1).

We will now have to differentiate S(r) with respect to r, so, check below for the differentiation:

dS/dr = 2ar (r0 - r ) + ar^2 (-1 ) ---------;(2).

dS/dr = 2ar(r0) - 2ar^2 - ar^2.

dS/dr = - 3ar^2 + 2ar(r0) ------------------(3).

Note that dS/dr = 0.

Hence, - 3ar^2 + 2ar(r0) = 0.

Making ra the subject of the formula we have;

ra[ - 3r + 2r(0) ] = 0. -------------------------(4).

Hence, r = 0 and r = 2r(0) / 3.

If we take the second derivative of S(r) too, we will have;

d^2S/dr = -6ar + 2ar(0). -------------------(5).

+ 2ar(0) > 0 for r = 0; and r = 2r(0)/3 which is the greatest.

Answer:

[tex]r =\frac{2r_{0}}{3}[/tex]

Step-by-step explanation:

We need to take the derivative of S(r) and equal to zero to maximize the function. In this conditions we will find the radius r for which the speed of the air is greatest.

Let's take the derivative:

[tex]\frac{dS}{dr}=a(2r(r_{0}-r)+r^{2}(-1))[/tex]

[tex]\frac{dS}{dr}=a(2r*r_{0}-2r^{2}-r^{2})[/tex]

[tex]\frac{dS}{dr}=a(2r*r_{0}-3r^{2})[/tex]

[tex]\frac{dS}{dr}=ar(2r_{0}-3r)[/tex]

Let's equal it to zero, to maximize S.

[tex]0=ar(2r_{0}-3r)[/tex]

We will have two solutions:

[tex]r = 0[/tex]

[tex]r =\frac{2r_{0}}{3}[/tex]

Therefore the value of r for which the speed of the air is greatest is [tex]r =\frac{2r_{0}}{3}[/tex].

I hope it helps you!