The stem-and-leaf plot lists the ages of customers in a bookstore.

How many customers are 19 or younger?



Enter your answer in the box.

Answer:

(8.213 ; 8.247)

Step-by-step explanation:

Given the data :

No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Dia. 8.23 8.16 8.23 8.25 8.26 8.23 8.20 8.26 8.19 8.23 8.20 8.28 8.24 8.25 8.24

Sanple size, n = 15

Sample mean, xbar = Σx / n = 123.45 / 15 = 8.23

The sample standard deviation, s = √(x -xbar)²/n-1

Using calculator :

Sample standard deviation, s = 0.03116

s = 0.031 (3 decimal places)

The 95% confidence interval :

C.I = xbar ± (Tcritical * s/√n)

Tcritical at 95%, df = 15 - 1 = 14

Tcritical = 2.145

C.I = 8.23 ± (2.145 * 0.031/√15)

C.I = 8.23 ± 0.0171689

C.I = (8.213 ; 8.247)

9514 1404 393

Answer:

  (11, -13)

Step-by-step explanation:

If midpoint M is halfway between A and B:

  M = (A +B)/2

Then B is ...

  B = 2M -A

  B = 2(4, -9) -(-3, -5) = (8+3, -18+5)

  B = (11, -13)

Answer:

Use the midpoint formula:

[tex]midpoint=(\frac{x_{1}+x_{2}}{2}, \frac{y_{1}+y_{2}}{2})[/tex]

Substitute in the values:

[tex](4, -9)=(\frac{-3+x_{2}}{2} +\frac{-5+y_{2}}{2} )[/tex]

[tex]4=\frac{-3+x_{2}}{2} \\4(2)=-3+x_{2}\\8+3=x_{2}\\x_{2}=11[/tex]      [tex]-9=\frac{-5+y_{2}}{2} \\(-9)(2)=-5+y_{2}\\-18+5=y_{2}\\y_{2}=-13[/tex]

Therefore, Point B = (11, -13)

Answer:

x = 74.74 m

Step-by-step explanation:

you need simple trigonometry to solve it

cosine of an angle is the ratio of the adjacent side to the hypotenuse

cos(42.2) is about 0.74

so X / Hypotenuse = 0.74

we know hypotenuse is 101 m

X / 101 = 0.74

x = 74.74 m

hope this helped!

Answer:

Cluster Sampling

Step-by-step explanation:

Cluster Sampling involves the random sampling of observation or subjects, which are subsets of a population. Cluster analysis involves the initial division of population subjects into a number of groups called clusters . From the divided groups or clusters , a number of groups is then selected and it's elements sampled randomly. In the scenario above, the divison of the population into towns where each town is a cluster. Then, the selected clusters (12) which are randomly chosen are analysed.

Answer:

d) Asking questions to make sure they understand what's being said

Step-by-step explanation:

Asking questions is important for learning and clears up any confusion.

Answer:

FH ≈ 6.0

Step-by-step explanation:

Using the sine ratio in the right triangle

sin49° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{FH}{FG}[/tex] = [tex]\frac{FH}{8}[/tex] ( multiply both sides by 8 )

8 × sin49° = FH , then

FH ≈ 6.0 ( to the nearest tenth )

Answer:

6

Step-by-step explanation:

sin = opposite/hypotenuse

opposite = sin * hypotenuse

sin (49) = 0,75471

opposite = 0,75471 * 8 = 6,037677 = 6

Answer:

0

Step-by-step explanation:

[tex]f(x)=2x-4\\f(2)=2(2)-4\\f(2)=4-4\\f(2)=0[/tex]

Answer:

0

Step-by-step explanation:

If f(x) = 2x - 4

Then f(2) = 2(2) -4

f(2) = 4 - 4

= 0

9514 1404 393

Answer:

  all real numbers

Step-by-step explanation:

The domain of any exponential function is "all real numbers". Reflecting the graph across the y-axis, by replacing x by -x does not change that.

The domain of g(x) = f(-x) is all real numbers.

Answer:

14.7

Step-by-step explanation:

tan(73)=48/x

or, x=48/tan(73)

or, x=14.7 (rounded to the nearest tenth)

Answered by GAUTHMATH

Answer:

11 meters

Step-by-step explanation:

First, we can say that the square has a side length of x. The perimeter of the square is 4x, and that is how much wire goes into the square. To maximize the area, we should use all the wire possible, so the remaining wire goes into the triangle, or (11-4x).

The area of the square is x², and the area of an equilateral triangle with side length a is (√3/4)a². Next, 11-4x is equal to the perimeter of the triangle, and since it is equilateral, each side has (11-4x)/3 length. Plugging that in for a, we get the area of the equilateral triangle is

(√3/4)((11-4x)/3)²

= (√3/4)(11/3 - 4x/3)²

= (√3/4)(121/9  - 88x/9 + 16x²/9)

= (16√3/36)x² - (88√3/36)x + (121√3/36)

The total area is then

(16√3/36)x² - (88√3/36)x + (121√3/36) + x²

= (16√3/36 + 1)x² -  (88√3/36)x + (121√3/36)

Because the coefficient for x² is positive, the parabola would open up and the derivative of the parabola would be the local minimum. Therefore, to find the maximum area, we need to go to the absolute minimum/maximum points of x (x=0 or x=2.75)

When x=0, each side of the triangle is 11/3 meters long and its area is

(√3/4)a² ≈ 5.82

When x=2.75, each side of the square is 2.75 meters long and its area is

2.75² = 7.5625

Therefore, a maximum is reached when x=2.75, or the wire used for the square is 2.75 * 4 = 11 meters

The length of the square must be 4 m in order to maximize the total area.

When we put the differentiation of the given function as zero and find the value of the variable we get maxima and minima.

We have,

Length of the wire = 11 m

Let the length of the wire bent into a square = x.

The length of the wire bent into an equilateral triangle = (11 - x)

Now,

The perimeter of a square = 4 side

4 side = x

side = x/4

The perimeter of an equilateral triangle = 3 side

11 - x = 3 side

side = (11 - x)/3

Area of square = side²

Area of equilateral triangle = (√3/4) side²

Total area:

T = (x/4)² + √3/4 {(11 -x)/3}² _____(1)

Now,

To find the maximum we will differentiate (1)

dT/dx = 0

2x/4 + (√3/4) x 2(11 - x)/3 x -1 = 0

2x / 4 - (√3/4) x 2(11 - x)/3 = 0

2x/4 - (√3/6)(11 - x) = 0

2x / 4 = (√3/6)(11 - x)

√3x = 11 - x

√3x + x = 11

x (√3 + 1) = 11

x = 11 / (1.732 + 1)

x = 11/2.732

x = 4

Thus,

The length of the square must be 4 m in order to maximize the total area.

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Answer:

Answer: -2

Step-by-step explanation:

g(-4) + f(1) = 7 + (-9) = 7 - 9 = -2

Answer:

D. 77

Step-by-step explanation:

We have to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.98}{2} = 0.01[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a p-value of [tex]1 - 0.01 = 0.99[/tex], so Z = 2.327.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

The population standard deviation is estimated to be $300

This means that [tex]\sigma = 300[/tex]

If a 98% confidence interval is used and the maximum allowable error is $80, how many cardholders should be sampled?

This is n for which M = 80. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]80 = 2.327\frac{300}{\sqrt{n}}[/tex]

[tex]80\sqrt{n} = 2.327*300[/tex]

[tex]\sqrt{n} = \frac{2.327*300}{80}[/tex]

[tex](\sqrt{n})^2 = (\frac{2.327*300}{80})^2[/tex]

[tex]n = 76.15[/tex]

Rounding up:

77 cardholders should be sampled, and the correct answer is given by option d.

Answer:

b) two-sample z-test for proportions

Step-by-step explanation:

The most appropriate test to use for the research hypothesis stated above is the two sample z-test for proportions, this is because, the experiment has two independent groups (male and female) with the result of each group not affecting the result of the other. The experiment clearly stses that, it is to estimate the difference in proportion, hence, it is a test of proportions rather than mean. Also when performing, a two sample tests of proportion, the Z distribution is used.

The number of sides of a regular polygon with an interior angle [tex]\[{178^ \circ }\][/tex] is 180.

A polygon is regular when all angles are equal and all sides are equal.

A regular polygon has if each interior angle.

Interior angle of given polygon =178

An exterior angle of polygon =180 −178 =2

The sum of exterior angles of any polygon is 360

Number of sides of a regular polygon

[tex]=\frac{360}{2}[/tex]

[tex]=180[/tex]

Therefore, The number of sides of a regular polygon is 180.

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​

Answer: lol ez

B.

Step-by-step explanation: XD

Answer:

D

Step-by-step explanation:

The general formula for the sine or cosine function is

y = A*Sin(Bx + C) + D

C = 0 in this case

B = pi / 3

The period is given by the formula

P = 2 * pi / B

P = 2 * pi//pi/3

The 2 pis cancel and you are left with 2*3 = 6

Answer:

D. There is no x value as there is no solution to this system

Step-by-step explanation:

2x − 3y = 3                                  5x − 4y = 4

5x - 4y = 4               -4y = -5x + 4                         y = 5/4x - 1

2x - 3(5/4x - 1) = 3

2x - 15/4x + 3 = 3

-7/4x = 0

x = 0

Answer:

a) 75.8% of students would score less than 550 in a typical year.

b) The comparable standard would be a minimum ACT score of 22.2.

c) 0.0139 = 1.39% probability that a randomly selected student will score over 700 on the SAT math test.

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Question a:

SAT, so mean of 480 and standard deviation of 100, that is, [tex]\mu = 480, \sigma = 100[/tex]

The proportion is the p-value of Z when X = 550. So

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

[tex]Z = \frac{550 - 480}{100}[/tex]

[tex]Z = 0.7[/tex]

[tex]Z = 0.7[/tex] has a p-value of 0.758.

0.758*100% = 75.8%

75.8% of students would score less than 550 in a typical year.

b. What would the engineering school set as comparable standard on the ACT math test?

ACT, with a mean of 18 and a standard deviation of 6, so [tex]\mu = 18, \sigma = 6[/tex]

The comparable score is X when Z = 0.7. So

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

[tex]0.7 = \frac{X - 18}{6}[/tex]

[tex]X - 18 = 0.7*6[/tex]

[tex]X = 22.2[/tex]

The comparable standard would be a minimum ACT score of 22.2.

c. What is the probability that a randomly selected student will score over 700 on the SAT math test?

This is 1 subtracted by the p-value of Z when X = 700, so:

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

[tex]Z = \frac{700 - 480}{100}[/tex]

[tex]Z = 2.2[/tex]

[tex]Z = 2.2[/tex] has a p-value of 0.9861.

1 - 0.9861 = 0.0139

0.0139 = 1.39% probability that a randomly selected student will score over 700 on the SAT math test.

Answer: The second one

Step-by-step explanation:

response/25=x/100 and then you solve for x

A percentage is a way to describe a part of a whole. The correct table is B.

A percentage is a way to describe a part of a whole. such as the fraction ¼ can be described as 0.25 which is equal to 25%.

To convert a fraction to a percentage, convert the fraction to decimal form and then multiply by 100 with the '%' symbol.

Given the number of students who play different sports as,

Basketball = 4

Football = 7

Lacrosse = 3

Soccer = 8

Volleyball = 3

Now, the percentage of students for each sport can be written as,

Basketball = 4/25 = 0.16

Football = 7/25 = 0.28

Lacrosse = 3/25 = 0.12

Soccer = 8/25 = 0.32

Volleyball = 3/25 = 0.12

Hence, the correct table is B.

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Answer:

No solution.

Step-by-step explanation:

[tex]{ \sf{y = ±∞ \: \: and \: \: x = ±∞}}[/tex]

9514 1404 393

Answer:

  D.  y=2x+6​

Step-by-step explanation:

The line cannot intersect the parabola if it has a y-intercept greater than 5 and a suitable slope. The only sensible answer choice is ...

  y = 2x +6

Answer:

D. y = 2x + 6.

Step-by-step explanation:

The required equation would not intersect the parabola at any point.

The only one to fit that is D.

Answer:

Step-by-step explanation:

Let's fill that in with what the variables are "worth":

(3)(-3)+2(-2) and simplify to

-9 + (-4) which, when you add those 2 negatives, gives you

-13, choice B.

Answer:

[tex]x = 3 \\ y = - 3 \\ z = - 2 \\ xy + 2z = 3 \times - 3 + 2 \times - 2 \\ = - 9 - 4 \\ = - 13 \\ thank \: you[/tex]

Answer: Choice A.)   88.2 < μ < 93.0

=============================================================

Explanation:

We have this given info:

Because n > 30 and because we know sigma, this allows us to use the Z distribution (aka standard normal distribution).

At 99% confidence, the z critical value is roughly z = 2.576; use a reference sheet, table, or calculator to determine this.

The lower bound of the confidence interval (L) is roughly

L = xbar - z*sigma/sqrt(n)

L = 90.6 - 2.576*8.9/sqrt(92)

L = 88.209757568781

L = 88.2

The upper bound (U) of this confidence interval is roughly

U = xbar + z*sigma/sqrt(n)

U = 90.6 + 2.576*8.9/sqrt(92)

U = 92.990242431219

U = 93.0

Therefore, the confidence interval in the format (L, U) is approximately (88.2, 93.0)

When converted to L < μ < U format, then we get approximately 88.2 < μ < 93.0 which shows that the final answer is choice A.

We're 99% confident that the population mean mu is somewhere between 88.2 and 93.0

Answer:

Should be (B)

01-1020

ED2021

The correct label for the population is 1 - 1020,

Option A is the correct answer.

It is the way of choosing a number of required items from a number of population given.

Each items has an equal probability of being chosen.

We have,

The population in this case refers to the entire group of interest, which is the entire student body of the school.

The total number of students is 1,020.

The population is usually labeled with a range or interval that includes all the possible values of the variable of interest.

In this case, the variable of interest is whether or not a student has an opinion on parking.

The correct label for the population is 1-1020, as this range includes all possible student identification numbers at the school.

The other options (01-1020, 001-1020, and 0001-1020) are not correct because they suggest that there are leading zeros in the student identification numbers, which is not usually the case.

Thus,

The correct label for the population is 1-1020,

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Answer:

2/52=1/26

Step-by-step explanation:

Answer:

The butter for one portion cost $ 0.375.

Step-by-step explanation:

Given that you buy butter for $ 3 a pound, and one portion of onion compote requires 2 oz of butter, to determine how much does the butter for one portion cost, the following calculation must be performed:

2 oz = 0.125 lb

1 = 3

0.125 = X

3 x 0.125 = X

0.375 = X

Therefore, the butter for one portion cost $ 0.375.

Answer:

x = 1; y=6

Step-by-step explanation:

y = 2x +4

3x + y = 9

Substitute 2x+4 for y in 3x+y = 9

3x + y = 9

3x + 2x+4 = 9

5x + 4 = 9

5x = 9-4

5x = 5

5x/5 = 5/5

x = 1

Substitute 1 for  x in y = 2x +4

2(1) + 4

2 + 4

= 6

Answered by Gauthmath