A study is done to find the 95% confidence interval for the difference in means between the ACT scores between two schools in a given city. One school had a random sample of 39 students had a sample mean of 25.90 with a sample standard deviation of 3.49. The second school had a random sample of 37 students had a sample mean 27.70 with a sample standard deviation of 2.47. What is the lower bound of the 95% confidence interval for the difference in means

Answers

Answer 1

Solution :

95% confidence interval for the difference between the means of ACT scores between two schools, is given by :

[tex]$[(\overline X_1 - \overline X_2)-ME, (\overline X_1 - \overline X_2)+ME]$[/tex]

[tex]$\overline X_1 = 25.90 , \ \ \ \overline X_2 = 27.70$[/tex]

[tex]$S_1=3.49, \ \ \ S_2 = 2.47$[/tex]

[tex]$n_1=39, \ \ n_2=37$[/tex]

M.E. , Margin of error,

[tex]$=t_{n_1+n_2-2,0.025} \times \left( s \sqrt{\frac{1}{n_1}+\frac{1}{n_2}}$[/tex]

[tex]$s^2 = \frac{(n_1-1)S_1^2+(n_2-1)S^2_2}{n_1+n_2-2}$[/tex]

  [tex]$=\frac{38(3.49)^2+36(2.47)^2}{39+37-2}$[/tex]

 = 9.222

s = 3.03

[tex]$t_{74,0.05} = 1.99$[/tex]

[tex]$M.E. = 1.99 \times 3.03 \times \sqrt{\frac{1}{39}+\frac{1}{37}}$[/tex]

        = 1.4

Therefore, 95% CI = [(25.90-27.70) - 1.4 , (25.90-27.70) + 1.4]

                              = [-3.2, -0.4]

Therefore, the lower bound is -3.2


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What is the answer to this question

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the answer is (x - 8) • (2x + 1)

Pam says that the temperature of liquid drops more in the first three minutes of cooling then it does between time nine minutes and time 12 minutes. Is pam correct give a reason for your answer

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Answer:

Pam is correct!

Step-by-step explanation:

Pam is correct it would be between nine minutes and 12!

What single transformation was applied to triangle A to get triangle B? Links will be reported​

Answers

Answer:

Rotation:

Step-by-step explanation:

Translation is usually movements like up, down, left, right.

Dilation is when one shape is bigger/smaller than the other, but still congruent.

Reflections are usually done over an axis (x or y), and don't change the degree at which a shape is turned. From looking at the triangles, you can see that one triangle was turned clockwise.

A farmer wants to know the effect of using various amounts of fertilizer in relation to the yield of his crops. He subdivided a portion of his land into 10 separate, but essentially equal, plots. He divided the land so that all of the plots had equal exposure to sun, rain, and other environmental conditions. He randomly selected 2 of the 10 plots and spread 2 pounds of fertilizer over each of them. Then he randomly selected 2 of the remaining plots and spread 3 pounds of fertilizer over each of them. He continued with the last sets of plots in the same manner, spreading 4, then 5, then 6 pounds of fertilizer over each of them. Below is a computer output for linear regression of amount of fertilizer versus yield for the 10 plots of land.

Predictor Coef SE Coef T P
Constant 10.100 0.7973 12.67 0.000
Fertizer 1.50 0.1879 6.12 0.000

S= 0.8404; R-Sq= 82.4% R-Sq(adj) = 80.28%

Required:
What is the equation of the least squares regression line from this sample?

Answers

Answer:

Y = 10.1 + 1.50x

Step-by-step explanation:

From the data contained in the computer output for linear regression

The coefficient of intercept = 10.1

coefficient of fertilizer = 1.50

Sample of an Equation of least squares regression line

y = a + bx

where : a = intercept , b = slope

hence the required equation will be

Y = 10.1 + 1.50x

y = yield , x = fertilizer

30)
The variable y is directly proportional to the variable x. If y = 12 when x = 14, what is the value of x when y = 747

Answers

Answer:

871.5

Step-by-step explanation:

directly proportional

y = kx

y = 12 when x = 14

12 = k(14)

k = 12/14

k = 6/7

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

what is the value of x when y = 747

747 = (6/7) * x

Multiply both sides by 7/6

747 * 7/6 = x

871.5 = x

the product of 6 less than a number and 4 more than the
number

Answers

Answer:

(x-4)(x+8)

Step-by-step explanation:

A translation is applied to the triangle formed by the points A (-1,4), B(-1,10), and C(3,6). The image is the triangle that has vertices. A’(3,4), B’(3,10), and C’(7,6).

The triangle was translated…

The answers:

4 units to then left

4 units up

4 units to the right

4 units down


Answers

4 units up i believe

The school that Emily goes to is selling tickets to the annual dance competition.

On the first day of ticket sales the school sold 3 senior citizen tickets and 14 child tickets for a total of $145.

The school took in $178 on the second day by selling 6 senior citizen tickets and 14 child tickets.

Find the price of a senior citizen ticket and the price of a child ticket.

Answers

Answer:

price for senior citizen is $11

price for child ticket is $8

HELP ME PLEASEEEEEEEEEEEE

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Answer:

20 feet

Step-by-step explanation:

[tex]1)\ A = \frac{b * h}{2}[/tex]

[tex]2)\ 120 = \frac{12b}{2}[/tex]

[tex]3)\ 12b = 240[/tex]

[tex]4)\ b = 20[/tex]

What is the slope of the line

Answers

Answer:

3

Step-by-step explanation:

Nathan is a recreational cyclist. He can travel 10 miles in one hour on his bicycle. Which graph represents the number of miles Nathan can travel in x hours?

Answers

Answer:

See attachment for graph

Step-by-step explanation:

Given

[tex]1\ hr = 10\ miles[/tex]

Required

The graph that shows the number of miles in x hours

We have:

[tex]1\ hr = 10\ miles[/tex]

Multiply both sides by x

[tex]x * 1hr = 10miles * x[/tex]

[tex]xhr=10x\ miles[/tex]

So, the function is:

[tex]f(x) =10x[/tex]

Which is the graph of f(x) = 3x?

Answers

Answer: (0,0) (1,3)
Step by step:
Rewrite the function as an equation- y=3x
Use slope intercept form to find slope and y-intercept. Slope: 3; Y-Intercept:0,0

Enter the values for the highlighted variables to
complete the steps to find the sum:
az
b =
3x 9
+
2x - 6 6 - 2x
CE
d =
3 x
9
+
2x-6 al 2x-6)
3x b.
+
2x-6 2x - 6
3х – с
2x-6
d{x - e)
f(x-3)
= 9
e =
f=
III
g=
DONE

Answers

Answer:

a = - 1

b = - 9

c = 9

d = 3

e = 3

f = 2

g = 3/2

Step-by-step explanation:

For a;

6 - 2x = - (2x - 6)

For b;

-1 * 9 = - 9

For x ;

3x + (-9) = 3x - 9

3x - 9 = d(x - e)

Factorizing :

3(x - 3)

d = 3 ; e = 3

2x - 6 = f(x - 3)

Factorize :

2x - 6 = 2(x - 3)

3(x - 3) / 2(x - 3)

g = 3/2

helppppp! how do I find this?

Answers

Answer:

y=3x-6

Step-by-step explanation:

(2,0). y=mx+b or 0=3 × 2+b, or solving for b: b=0-(3)(2). b=-6.

(3,3). y=mx+b or 3=3 × 3+b, or solving for b: b=3-(3)(3). b=-6.

Plugging in the two points from the graph.

Hence, y=3x-6

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First you would do base times night with is 224. Then you would divide 224 by 2, so your answer would be 112

Answer:

The area is 112.

Step-by-step explanation:

14 x 16 = 224

224/2 = 112

Consider this expression (x+9)(x-2)-9×_6
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Answers

Answer:

x^2 -2x-24

Step-by-step explanation:

Answer: (x+4)(x-6)

Step-by-step explanation: Plato Answer

What is the place value of 9 in the number 8.0231497?

Answers

Answer:

Tens

Step-by-step explanation:

it’s really easy if you know your place values just go ones,tens,hundreds,thousands and keep going but the answer is tens place.

Find the area of the composite figure.
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B. 720 sq m
C. 1000 sq m
D. 1152

Answers

Answer:

B 720 sq m

Step-by-step explanation:

A= 24^2 + 12^2

= 720 sq m

Are the polynomial functions even or odd ?

Answers

If you mirror the graph along the x axis and it lies on itself ( mirror image) it is even, if not it is odd.

If you mirror the top graph the high/ low points would be opposite so the top graph is odd

The bottoms graph can be mirrored so the bottom graph is even.

The mean temperature for the first 7 days in January was 6 °C.
The temperature on the 8th day was 3 °C.
What is the mean temperature for the first 8 days in January?

Answers

Answer:

GIME SOME POINTS

Step-by-step explanation:

Answer:

Step-by-step explanation:

The answer is 4.5

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Answers

Answer:

16

Step-by-step explanation:

Write at least three expressions that are equivalent to 3(2x - 5)

Answers

Answer:

6x - 15

6x - (5 · 3)

(3 · 2x) - 15

So, for #1, we can just simplify 3(2x - 5) to get another expression:

3(2x - 5),

6x-15

For the next one, we could make a new equation that equals 6x-15:

(3x)+(3x)+(5 *-3)

Then for the last one, how about rewrite it so all of the values are inversely negated?

3(2x - 5),

-3(-2x +5)

Hey I need some help with this

Answers

Answer:

with what plz explain the question

if sides of a triangle have lengths 8 ft and 12 ft.

Answers

Answer:

[tex]20 > c > 4[/tex]

Step-by-step explanation:

Given

[tex]Sides =8\ and\ 12[/tex]

Required

The third side

To do this, we make use of the triangle inequality theorem which implies that:

[tex]a + b > c[/tex]

[tex]a + c > b[/tex]

[tex]b + c > a[/tex]

Where

[tex]a,b,c\to sides[/tex]

So, we have:

[tex]8 + 12 > c[/tex]

[tex]8 + c > 12[/tex]

[tex]12 + c > 8[/tex]

Solve all inequalities

[tex]8 + 12 > c[/tex]

[tex]20 > c[/tex]

[tex]8 + c > 12[/tex]

[tex]c > 4[/tex]

[tex]12 + c > 8[/tex]

[tex]c > -4[/tex]

Ignore negative inequalities.

So, we have:

[tex]20 > c[/tex] and [tex]c > 4[/tex]

Combine

[tex]20 > c > 4[/tex]

The above implies that the third length is between 5 and 19 (inclusive)

Help pls.......asap i have 2 minuets

Answers

Answer:

It would be 3 1/2!

Step-by-step explanation:

Because it is X by Y (Usually) AKA bottom row to side row so, it is in the middle of 3 and 4 so it would be 3 1/2!

Answer:

( 3, 3.5) or 3 1/2

Step-by-step explanation:

The cordinate is ( 3, 3.5) but if it has a fraction form like your question had all you want to do is convert 3.5 into a fraction. 3.5 into a fraction is 3 1/2 the 0.5 becomes 1/2 and the 3 is a 3. So the answer is 3 1/2 or ( 3, 3.5).

If the circumference of a circle is 44 cm, find its area​

Answers

Answer: 154 sq cm

Step-by-step explanation:

what is
1/3 x (15+6)

Answers

Answer:

First, you do 15+6 (because of the parentheses)

You get 21

then you have to do 1/3 times 21 and you get 7

Answer:

7

Step-by-step explanation:

Using BODMAS which stands for:

(Bracket, of, Division, Multiplication, Addition and Subtraction)

We first treat the bracket

  (15+6)=21

We then treat the division

(but it is already reduced to its lowest terms therefore no need, but if you like you can reduce it to a decimal though)

[tex]\frac{1}{3}[/tex]

Then we move onto the multiplication which is the last part

[tex]\frac{1}{3}[/tex] ×21= [tex]\frac{21}{3}[/tex] =7

URGENT NEED THIS DONE FAST LINKS WILL BE REPORTED

Answers

x=3
2 times 3 equals 6

[tex]\pink{\bold{\underline{\underline{hello ♡}}}}[/tex]

Since 2x = 6, we have to divide each side by 2 to find x.

6÷2= 3

Our answer is 3.

Solvex2
- 4x=21
using the zero product property.

Answers

Answer:

The answer is (x + 3) (x - 7) = 0

Step-by-step explanation:

x² - 4x = 21

x² - 4x - 21 = 0

x² - 7x + 3x - 21 = 0

x(x - 7) + 3(x - 7) = 0

(x + 3) (x - 7) = 0

Thus, The answer is (x + 3) (x - 7) = 0

-TheUnknownScientist

How far from the base of the house do you need to place an 18’ ladder so that it exactly reaches the top of a 14’ wall?

Answers

Answer:

Length of Ladder(Hypotenuse)=18

Height of wall(Opposite) =14

How far from the base... This talks about the adjacent or distance between the wall and the base.

You can get your answer from Pythagoras theorem

Which states

The square of the hypotenuse is = to the squares of the adjacent and Opposite sides

H² = O² + A²

We're looking for the adjacent "A"

Making A the subject

A² = H² - O²

A= √H² - O²

A= √18² - 14²

A=√128

A= 8√2'

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