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3 years ago

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Ms Jenkins art class has 35 students in art class.7 of the 35 students are girls.What percentage of the class is made up of boys

?

1 answer:

lubasha [3.4K]3 years ago

3 0

28 boys I think ‍♀️.

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Express the confidence interval 0.555 less than 0.777 in the form Modifying above p with caret plus or minus Upper E.

Elina [12.6K]

Complete Question

Express the confidence interval 0.555 less than p less than 0.777 in the form Modifying above p with caret plus or minus Upper E.

Answer:

The modified representation is $\r p \pm E = 0.666 \pm 0.111$

Step-by-step explanation:

From the question we are told that

The confidence interval interval is $0.555 < p < 0.777$

Now looking at the values that make up the up confidence interval we see that this is a symmetric confidence interval(This because the interval covers 95% of the area under the normal curve which mean that the probability of a value falling outside the interval is 0.05 which is divided into two , the first half on the left -tail and the second half on the right tail as shown on the figure in the first uploaded image(reference - Yale University ) ) which means

Now since the confidence interval is symmetric , we can obtain the sample proportion as follows

$\r p = \frac{0.555 + 0.777}{2}$

$\r p =0.666$

Generally the margin of error is mathematically represented as

$E = \frac{1}{2} * K$

Where K is the length of the confidence interval which iis mathematically represented as

$K = 0.777 -0.555$

$K = 0.222$

Hence

$ME = \frac{1}{2} * 0.222$

$ME = 0.111$

So the confidence interval can now be represented as

$\r p \pm E = 0.666 \pm 0.111$

3 0

4 years ago

Does each function describe exponential growth or decay?

zhannawk [14.2K]

Hey Jinx :)

------------------------------------------------

Note that a decay has a rate between 0 and 1, and a growth as a rate of 1 or higher.

y = 1/2(1 + 0.03)^t → y = 1/2(1.03)^t (Rate is more then 0) GROWTH

y = 0.3(0.95)^t → (Rate is between 0 and 1) DECAY

y = ((1+0.03)^1/2)^2t → y = y = 1.014^2t (Rate is more then 0) GROWTH

y = 200(0.73)^t → (Rate is between 0 and 1) DECAY

y = 4(1/4)^t → (Rate is between 0 and 1) DECAY

------------------------------------------------

Hope This Helped! Good Luck!

4 0

3 years ago

PLZZ HELP bubba biked 19 kilometers how far did he bike in miles? A mile is approximately 1.6 kilometers Round to the nearest te

alekssr [168]

11.8 miles............

8 0

3 years ago

Read 2 more answers

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airp

motikmotik

Answer:

The 95% confidence interval for the population mean rating is (5.73, 6.95).

Step-by-step explanation:

We start by calculating the mean and standard deviation of the sample:

$M=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\M=\dfrac{1}{50}(6+4+6+. . .+6)\\\\\\M=\dfrac{317}{50}\\\\\\M=6.34\\\\\\s=\sqrt{\dfrac{1}{n-1}\sum_{i=1}^n\,(x_i-M)^2}\\\\\\s=\sqrt{\dfrac{1}{49}((6-6.34)^2+(4-6.34)^2+(6-6.34)^2+. . . +(6-6.34)^2)}\\\\\\s=\sqrt{\dfrac{229.22}{49}}\\\\\\s=\sqrt{4.68}=2.16\\\\\\$

We have to calculate a 95% confidence interval for the mean.

The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.

The sample mean is M=6.34.

The sample size is N=50.

When σ is not known, s divided by the square root of N is used as an estimate of σM:

$s_M=\dfrac{s}{\sqrt{N}}=\dfrac{2.16}{\sqrt{50}}=\dfrac{2.16}{7.071}=0.305$

The degrees of freedom for this sample size are:

$df=n-1=50-1=49$

The t-value for a 95% confidence interval and 49 degrees of freedom is t=2.01.

The margin of error (MOE) can be calculated as:

$MOE=t\cdot s_M=2.01 \cdot 0.305=0.61$

Then, the lower and upper bounds of the confidence interval are:

$LL=M-t \cdot s_M = 6.34-0.61=5.73\\\\UL=M+t \cdot s_M = 6.34+0.61=6.95$

The 95% confidence interval for the mean is (5.73, 6.95).

4 0

4 years ago

What is all of the surface area and volume of this Castle? Find the surface area and volume of all the figures below, then out o

motikmotik

Answer:

Step-by-step explanation:

There are a few formulas that are useful for this:

lateral area of a pyramid or cone: LA = 1/2·Ph, where P is the perimeter and h is the slant height
lateral area of a cylinder: LA = π·dh, where d is the diameter and h is the height
area of a rectangle: A = lw, where l is the length and w is the width
volume of a cone or pyramid: V = 1/3·Bh, where B is the area of the base and h is the height
volume of a cylinder or prism: V = Bh, where B is the area of the base and h is the height

You will notice that for lateral area purposes, a pyramid or cone is equivalent to a prism or cylinder of height equal to half the slant height. And for volume purposes, the volume of a pyramid or cone is equal to the volume of a prism or cylinder with the same base area and 1/3 the height.

Since the measurements are given in cm, we will use cm for linear dimensions, cm^2 for area, and cm^3 for volume.

___

The heights of the cones at the top of the towers can be found from the Pythagorean theorem.

(slant height)^2 = (height)^2 + (radius)^2

height = √((slant height)^2 - (radius)^2) = √(10^2 -5^2) = √75 = 5√3

The heights of the pyramids can be found the same way.

height = √(13^2 -2^2) = √165

___

<u>Area</u>

The total area of the castle will be ...

total castle area = castle lateral area + castle base area

These pieces of the total area are made up of sums of their own:

castle lateral area = cone lateral area + pyramid lateral area + cylinder lateral area + cutout prism lateral area

and ...

castle base area = cylinder base area + cutout prism base area

So, the pieces of area we need to find are ...

cone lateral area (2 identical cones)
pyramid lateral area (2 identical pyramids)
cylinder lateral area (3 cylinders, of which 2 are the same)
cutout prism lateral area
cylinder base area (3 cylinders of which 2 are the same)
cutout prism base area

Here we go ...

Based on the above discussion, we can add 1/2 the slant height of the cone to the height of the cylinder and figure the lateral area of both at once:

area of one cone and cylinder = π·10·(18 +10/2) = 230π

area of cylinder with no cone = top area + lateral area = π·1^2 +π·2·16 = 33π

area of one pyramid = 4·4·(13/2) = 52

The cutout prism outside face area is equivalent to the product of its base perimeter and its height, less the area of the rectangular cutouts at the top of the front and back, plus the area of the inside faces (both vertical and horizontal).

outside face area = 2((23+4)·11 -3·(23-8)) = 2(297 -45) = 504

inside face area = (3 +(23-8) +3)·4 = 84

So the lateral area of the castle is ...

castle lateral area = 2(230π + 52) +33π + 504 + 84 = 493π +692

≈ 2240.805 . . . . cm^2

The castle base area is the area of the 23×4 rectangle plus the areas of the three cylinder bases:

cylinder base area = 2(π·5^2) + π·1^2 = 51π

prism base area = 23·4 = 92

castle base area = 51π + 92 ≈ 252.221 . . . . cm^2

Total castle area = (2240.805 +252.221) cm^2 ≈ 2493.0 cm^2

___

<u>Volume</u>

The total castle volume will be ...

total castle volume = castle cylinder volume + castle cone volume + castle pyramid volume + cutout prism volume

As we discussed above, we can combine the cone and cylinder volumes by using 1/3 the height of the cone.

volume of one castle cylinder and cone = π(5^2)(18 + (5√3)/3)

= 450π +125π/√3 ≈ 1640.442 . . . . cm^3

volume of flat-top cylinder = π·1^2·16 = 16π ≈ 50.265 . . . . cm^3

The volume of one pyramid is ...

(1/2)4^2·√165 = 8√165 ≈ 102.762 . . . . cm^3

The volume of the entire (non-cut-out) castle prism is the product of its base area and height:

non-cutout prism volume = (23·4)·11 = 1012 . . . . cm^3

The volume of the cutout is similarly the product of its dimensions:

cutout volume = (23 -8)·4·3 = 180 . . . . cm^3

so, the volume of the cutout prism is ...

cutout prism volume = non-cutout prism volume - cutout volume

= 1012 -180 = 832 . . . . cm^3

Then the total castle volume is ...

total castle volume = 2·(volume of one cylinder and cone) + (volume of flat-top cylinder) +2·(volume of one pyramid) +(cutout prism volume)

= 2(1640.442) + 50.265 +2(102.762) +832 ≈ 4368.7 . . . . cm^3

4 0

3 years ago