All categories

3 years ago

The question is in a screenshot please help ty

Mathematics

1 answer:

andrew-mc [135]3 years ago

4 0

The correct answer would be D. We know that A is incorrect because A shows that she would study for less than 1 1/4 hours. We know that B is incorrect because this shows that she can study exactly 1 1/4 hours. C is incorrect because even though the inequality is right, there are only 24 hours in a day so she cannot study up to 30 hours in one night.

Hope this helps

You might be interested in

The pentagonal prism has a perpendicular distance of 14 units between the bases. The volume of the prism is 840 cubic units. Wha

Leno4ka [110]

Answer:

Option 4. Perimeter = 30 units

Step-by-step explanation:

Since the volume of a pentagonal prism is 840 cubic units.

Perpendicular distance between the bases = 14 units

We know volume of a pentagonal prism = Area of base × distance between the bases

840 = Area × 14

Area = 840/14 = 60 square units

Now area of a pentagon

$A=\frac{a^{2}}{4}\times\sqrt{5(5+2\sqrt{5})}$

$1.72a^{2}=60$

$a^{2}=\frac{60}{1.72}=34.90$

$a=\sqrt{34.9}=5.91$

Therefore perimeter of the pentagon = 5×a = 5×5.91 = 29.54 ≈ 30 units

8 0

3 years ago

The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books check

Verdich [7]

Answer:

$n=(\frac{1.960(150)}{90})^2 =10.67 \approx 11$

So the answer for this case would be n=11 rounded up to the nearest integer

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma =150$ represent the population standard deviation

n represent the sample size

Solution to the problem

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

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The confidence interval for this case is given by: (740, 920)

We can find the estimate for the mean and we got:

$\bar X = \frac{740+920}{2} = 830$

and the margin of error is given by :

$ME = \frac{920-740}{2}= 90$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{s}{\sqrt{n}}$ (a)

And on this case we have that ME =90 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} s}{ME})^2$ (b)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got $z_{\alpha/2}=1.960$ , replacing into formula (b) we got:

$n=(\frac{1.960(150)}{90})^2 =10.67 \approx 11$

So the answer for this case would be n=11 rounded up to the nearest integer

5 0

2 years ago

Which of the following are congruence transformations? A.Shrinking B.Rotating C.Reflecting D.Stretching E.Translating

Soloha48 [4]

Answers:
Rotating
Reflecting
Translating

Explanation:
Congruence transformation is a transformation that does not change neither the side lengths nor the measures of the angles.
This means that the formed image is an exact copy of the original figure

Now, let's check the options:
1- Shrinking: This means that we are decreasing the side lengths.
This option is incorrect

2- Rotating: This means that we are just changing the orientation of the figure without altering any measurements.
This option is correct

3- Reflecting: This means that we are just changing the orientation of the figure without altering any measurements.
This option is correct

4- Stretching: This means that we are increasing the side lengths.
This option is incorrect

5- Translating: This means that we are just changing the position of the figure without altering any measurements.
This option is correct

Hope this helps :)

3 0

3 years ago

Read 2 more answers

The circumference of a circle C is directly proportional to its radius r. if the circumference of a circle whose radius is 5 inc

dedylja [7]

16 pi inches

Circumference is double the radius

5 0

3 years ago

Resolve into fraction: 2x²+5x+3

natali 33 [55]

Step-by-step explanation: