Answer:
See step by step explanation
Step-by-step explanation:
From the problem statement, we understand that we need to investigate if 2nd graders RETAIN OR LOSE knowledge comparing information concerning two different months, therefore we are going to find out if the information gives us enough evidence of a difference in the two groups
a) The test should be a two tail-test
Sample sizes are small ( n₁ = n₂ = 9 ) which means we have to use t-student test
b and c) Test Hypothesis:
For Null Hypothesis H₀, we establish that the two means are equal, which in this case means that the two samples´ means are equal. And as Hypothesis alternative Hₐ that the H₀ is not true, or that the samples mean are different.
Null Hypothesis H₀ x₁ - x₂ = 0 or x₁ = x₂
Alternative Hypothesis Hₐ x₁ - x₂ ≠ 0 or x₁ ≠ x₂
d) Significance level α = 0,05 then α/2 = 0,025
then t(c) with α/2 = 0,025 and degree of freedom
df = n₁ + n₂ - 2 df = 9 + 9 -2 df = 16
From t s-tudent table we find t(c) = 2,12
e) Calculating:
x₁ and σ₁
x₂ and σ₂
σₓ = [ ( n₁ - 1 )* σ₁² + ( n₂ - 1 )*σ₂² ]/ n₁ + n₂ - 2
Using a calculator:
x₁ = 77,11 σ₁ = 13,86
x₂ = 85,89 σ₂ = 12,74
σₓ = [ ( 8*(13,86)² + 8*( 12,74 )² ] / 16
σₓ = (8* 192,1) + 8* ( 162,31) / 16
σₓ = (1536,8 + 1298,48 ) / 16
σₓ = 177,205
t(s) = ( x₁ - x₂ ) /√ σₓ²/ n₁ + σₓ²/ n₂
t(s) = ( 77,11 - 85,89 )/ (177,205)²/n₁ + (177,205)²/n₂
t(s) = - 8,78 / √3489,07 + 3489,07
t(s) = -8,78 / 83,54
t(s) = - 0,11
Comparing t(s) and t(c)
|t(s)| < |t(c)|
0,11 < 2,12
t(s) is in the acceptance region. We accept H₀
A grocer wants to mix two kinds of coffee. One kind sells for $0.85 per pound, and the other sells for $2.70
per pound. He wants to mix a total of 21 pounds and sell it for $0.95 per pound. How many pounds of
each kind should he use in the new mix? (Round off the answers to the nearest hundredth.)
Answer:
x = $0.85 per pound = 19.85 pounds
y = $2.70 per pound = 1.14 pounds
Step-by-step explanation:
Let
x = $0.85 per pound
y = $2.70 per pound
x + y = 21 (1)
0.85x + 2.70y = 19.95 (2)
From (1)
x = 21 - y
Substitute x = 21 - y into (2)
0.85x + 2.70y = 19.95 (2)
0.85(21 - y) + 2.70y = 19.95
17.85 - 0.85y + 2.70y = 19.95
- 0.85y + 2.70y = 19.95 - 17.85
1.85y = 2.1
y = 2.1 / 1.85
y = 1.14
Substitute y = 1.14 into (2)
0.85x + 2.70y = 19.95
0.85x + 2.70(1.14) = 19.95
0.85x + 3.078 = 19.95
0.85x = 19.95 - 3.078
0.85x = 16.872
x = 16.872 / 0.85
x = 19.85
x = $0.85 per pound = 19.85 pounds
y = $2.70 per pound = 1.14 pounds
20 POINTS!!!!!The monthly salary of an employee with 33 hours of training can be written as
a)How many similar figures can be drawn inside the following figures?
Find the limit of area and perimeter
The Louvre pyramid in Paris is built of glass panes. The top row has 4 glass panes, and each row after it has 4 more panes than the previous row. How many panes of glass are in the 16th row?
Answer:
Number of glass panel in 16th row = 64
Step-by-step explanation:
Given:
Number of glass panel in first row = 4
Each next row added number of glass panel = 4
Find:
Number of glass panel in 16th row
Computation:
An = a + [n-1]d
An = given term = A16
a = first term = 4
n = number of term = 15
d = Common difference = 4
An = a + [n-1]d
An = 4 + [16-1]4
An = 4 + [15]4
An = 4 + 60
An = 64
Number of glass panel in 16th row = 64
Given that O is
the center of the
circle and line
segment XY is a
tangent line, find
the measure of
angle BAX.
Answer:
Step-by-step explanation:
ahh 30° is the mystery angle . sooo
180-30 = 150 that angle BOA
then the other two angle are each 15°
so then BAX is 90-15=75°
:)
Anyone smart at math?
Answer:
The function f(x) = 4.95x represents the cost to purchase x pounds of chocolate from a candy company. The function g(x) = 0.99x + 2.25 models the cost to ship x pounds of chocolate from the company. Write a function, h(x), that models the total cost to purchase and ship x pounds of chocolate from the company.
Step-by-step explanation:
boom it is big now
Please simplify this!
[tex]( {3}^{2}) {}^{3} [/tex]
Answer:
729
Step-by-step explanation:
We have the equation [tex](3^2)^3[/tex] and are asked to simplify it.
When you have a number with an exponent inside the parenthesis, and then another exponent right out of the parenthesis, you follow the rule where you multiply both exponents together.
Therefore,
[tex](3^2)^3=3^{2*3} =3^6[/tex]
[tex]3^6 = 729[/tex]
The jacket at the department store originally cost $199. It was selling so well that the store decided to increase the price by 25 percent. What was the new cost of the jacket?
Answer:
$248.75
Step-by-step explanation:
25% more of 199 is 248.75
A grocery store recently sold 10 cartons of yogurt, of which 5 were raspberry. What is the experimental probability that the next carton of yogurt sold will be raspberry?
Answer:
Step-by-step explanation:
10/16
What is the slope for the line that goes through the points?
(The answer should be a fraction (rise/run)
Answer: 2/1x
Step-by-step explanation:
you follow the graph from the y intercept to the next point
up 2 over 1
Answer:
2/1 or 2
Step-by-step explanation:
from point (0,2) to (1,4) it goes up 2 and to the left 1 so the rise is 2 and the run is 1
Pls help I’ll brainlest
Answer:
(D) 13/15
Step-by-step explanation:
Well there are 15 marbles in total.
There are 2 marbles that are blue
The qusection asks for the probability of NOT a blue
so 13/15
What is the value of x?
30
v
O 45
T
(3x) °
O 55
-40
R
O 60
w
Intro
Answer:45
Step-by-step explanation:
The value of x by the given data is 190/3 or 63.33
What is Algebra?Algebra is the study of abstract symbols, while logic is the manipulation of all those ideas.
The acronym PEMDAS stands for Parenthesis, Exponent, Multiplication, Division, Addition, and Subtraction. This approach is used to answer the problem correctly and completely.
We are given that;
The angles between the lines
Now,
To find the value of x, you need to use the fact that the sum of angles in a triangle is equal to 180°1. This means that:
30° + (3x)° + (-40)° = 180°
Simplifying, we get:
(3x)° - 10° = 180°
Adding 10° to both sides, we get:
(3x)° = 190°
Dividing both sides by 3, we get:
x = 190/3
Therefore, by algebra the answer will be 190/3 or 63.33.
More about the Algebra link is given below.
brainly.com/question/953809
#SPJ7
find the next number 2,5,12,25,54
Answer:
Step-by-step explanation:
The next number is 110
PLEASE HELPPP!!!!!!!!
Answer:
A
Step-by-step explanation:
If you get that right, follow Sammy Revv on Spotify please
Which phrase describes the shape of the data?
.
.
.
12
13
14
15
10
17
18
A. Symmetric, not bell-shaped
B. Not symmetric, bell-shaped
C. Not symmetric, not bell-shaped
D. Symmetric bell-shaped
Answer:
C. Not symmetric; not bell-shaped.
Step-by-step explanation:
In a symmetric data distribution, the shape on the left side is almost the same as the shape on the right side of the middle. In this type of data distribution, if different measure of centers are calculated (mean, median, and mode), they will have a similar figures that are close together. Symmetric distributions are bell-shaped.
On the other hand, if the data distribution is not symetric, it means the left and the right side of the distribution are not equal and do not have the same shape.
The data in the dot plot above is considered as NOT SYMMETRIC. Also, it is not bell-shaped.
Answer:
c
Step-by-step explanation:
Determine the median of the following numbers: 8, 11, 11, 12, 13, 15, 16, 16, 18, 21
Answer:
The median of the following numbers is 14
Step-by-step explanation:
Review the graph of function g(x).
On a coordinate plane, a line goes from open circle (0, 0) through (negative 4, 2). A curve goes from the open circle to (2, 1) and then down through open circle (4, 0). A closed circle is at (4, negative 2).
Which table identifies Limit as x approaches 0g(x) and Limit as x approaches 4g(x), if they exist?
Limit of g (x) as x approaches 0 0
Limit of g (x) as x approaches 4 0
Limit of g (x) as x approaches 0 DNE
Limit of g (x) as x approaches 4 DNE
Limit of g (x) as x approaches 0 0
Limit of g (x) as x approaches 4 −2
Limit of g (x) as x approaches 0 DNE
Limit of g (x) as x approaches 4 −2
Answer:
The Answer is A) 0,0
Step-by-step explanation:
I got it right!
Do -16 and 16 have the same value
Answer:
No they do not
Step-by-step explanation:
16 is positive -16 is negative they have different values. Hope this helps!
Help me please help ASAP help me ASAP please please help ASAP
Answer:
P = 10π + 30 ≈ 61.4
Step-by-step explanation:
Perimeter = s1 + s2 + s3 + s4
= πd/2 + 15 + πd/2 + 15 = 2 (5π + 15) = 10π + 30 ≈ 61.4
a firm has ebit of 1,000,000 and depreciation expense of 400,000. fixed charges total 600,000. interest expense totals 70,000. what is the firm cash coverage ratio.
Answer:
The firm's fixed-charge coverage ratio is 7.89 times
Explanation:
Fixed charge coverage ratio : This ratio deals with fixed payments like: interest payments, lease payments which is before earning before income and taxes.
The formula to compute the fixed charge coverage ratio is shown below:
= (EBIT + Fixed charges) ÷ (Fixed charges + interest expense)
= ($400,000 + $50,000) ÷ ($50,000 + $7,000)
= $450,000 ÷ $57,000
= 7.89 times
The total of fixed charge include depreciation expense also. Thus it would not be taken into computation part.
Hence, the firm's fixed-charge coverage ratio is 7.89 times
Solve the system of equations-y = -1 and -51 - 3y = -15 by combining the equations
Answer:
No solution
Step-by-step explanation:
-y = -1
-51 - 3y = -15
-3y = -15 + 51
-3y = 36
y = -12
y = 1
y = -12
No solution
For a quadrilateral to be a rhombus, the diagonals ______________ and ______________.
first blank choices:
must be congruent
must not be congruent
can be congruent or not congruent
second blank choices:
must be perpendicular
must not be perpendicular
can be perpendicular or not perpendicular
9514 1404 393
Answer:
can be congruent or not congruentmust be perpendicularStep-by-step explanation:
The diagonals of a rhombus are perpendicular bisectors of each other. If they are congruent, the rhombus is a square.
Your blanks can be filled with ...
can be congruent or not congruentmust be perpendicularWe would like to point out that these descriptors also apply to a kite. The figure will only be a rhombus if the diagonals bisect each other (as for any parallelogram).
Each triangle in the net has a base length that measures 6 inches and a height that measures 4 inches. What is the surface area of the pyramid that can be formed from this net? 12 inches squared 24 inches squared 36 inches squared 48 inches square
Answer:
Surface area of triangular pyramid = 48 inch²
Step-by-step explanation:
Given:
Base length of triangle = 6 inches
Height of triangle = 4 inches
Find:
Surface area of triangular pyramid
Computation:
Surface area of triangular pyramid = 4 x [Surface area of triangle]
Surface area of triangular pyramid = 4 x [(1/2)(b)(h)
Surface area of triangular pyramid = 4 x [(1/2)(6)(4)
Surface area of triangular pyramid = 4 x [(1/2)(24)]
Surface area of triangular pyramid = 4 x 12
Surface area of triangular pyramid = 48 inch²
Given the set of integers 1 − 20 , what is the probability of selecting a number that is divisible by 7 ?
The probability of selecting a number that is divisible by 7 is [tex]\frac{1}{10}[/tex].
What is probability?Probability deals with finding out the likelihood of the occurrence of an event.
It measures the chance of an event happening and is equal to the number of favorable events divided by the total number of events.
The value of probability ranges between 0 and 1, where 0 denotes uncertainty and 1 denotes certainty.
Given
Set of integers = 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
The probability of selecting a number that is divisible by 7 :
We all know the 7 multiples less than 20 : 7, 14
There are 2 numbers that are divisible by 7 in the set of integers 1 - 20
Therefore, Number of favorable outcomes n(E) = 2
Total number favorable outcomes n(S) = 20
Probability is the ratio of number of favorable outcomes to total number of favorable outcomes.
[tex]P(E) = \frac{n(E)}{n(S)}[/tex]
[tex]P(E) = \frac{2}{20} =\frac{1}{10}[/tex]
Hence,
The probability of selecting a number that is divisible by 7 is [tex]\frac{1}{10}[/tex].
Find out more information about probability here
https://brainly.com/question/14395172
#SPJ2
The variables x and y are inversely proportional, and y = 2 when x = 3. What is the value of y when x = 9?
Answer:
[tex] \huge \purple{ \boxed{ y = \frac{2}{3} }}[/tex]
Step-by-step explanation:
Since, the variables x and y are inversely proportional.
[tex] \therefore \: y \: \: \alpha \: \: \frac{1}{x} \\ \implies \: y = \frac{k}{x} \\ (k = constant) \\ \implies \: xy = k ...(1)\\ plug \: y = 2, \: \: x = 3 \: in \: equation \: (1) \\ we \: find \\ 2 \times 3 = k \\ k = 6 \\ plug \:k = 6 \: in \: equation \: (1) \\ xy = 6 \\ (this \: is \: the \: equation \: of \: variation) \\ when \: x = 9 \: \: y =? \\ \\ 9y = 6 \\ y = \frac{6}{9} \\ \huge \red{ \boxed{ y = \frac{2}{3} }}[/tex]
Help with this equation please
Answer:
[tex]y=-\frac{2}{3}x+6[/tex]
Step-by-step explanation:
Let the equation of the line representing the given table is,
y = mx + b
Here, m = slope of the line
b = y-intercept
From the given table,
Since, slope of the line passing through [tex](x_1,y_1)[/tex] and [tex](x_2,y_2)[/tex] is given by,
m = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]
Therefore, slope of the line passing through (3, 4) and (4, [tex]\frac{10}{3}[/tex]) will be,
m = [tex]\frac{4-\frac{10}{3} }{3-4}[/tex]
= [tex]\frac{\frac{12-10}{3}}{3-4}[/tex]
= [tex]-\frac{2}{3}[/tex]
Therefore, equation of the line will be,
[tex]y=-\frac{2}{3}x+b[/tex]
Since, this line passes through a point [tex](1, \frac{16}{3})[/tex],
By satisfying the equation with the given point,
[tex]\frac{16}{3}=-\frac{2}{3}(1)+b[/tex]
[tex]b=\frac{16}{3}+\frac{2}{3}[/tex]
[tex]b=\frac{18}{3}[/tex]
[tex]b=6[/tex]
Therefore, equation of the line will be,
[tex]y=-\frac{2}{3}x+6[/tex]
Helpppppppppppppppppppp
Answer:
192.5 m²
Step-by-step explanation:
The formula for calculating the area if a circle
= πr²
Find the area of the larger circle first, then subtract the area of the smaller circle.
The area of the larger circle
= π×(21÷2)²
= 346.4 m² (rounded to the nearest tenth)
The radius of the smaller circle
= 21÷2 - 3.5
= 7 m
The area of the smaller circle
= π×7²
= 153.9 m² (rounded to the nearest tenth)
The area of the shaded region
= 346.4 - 153.9
= 192.5 m²
Help with the question plz people
You are cheating. I see this is a test.
what is the square root of 377.68
Answer:
19.4339908408
HELP IM TIMED. ILL MARK BRAINLIEST!
Answer:
Step-by-step explanation:
Answer:
c
Step-by-step explanation:
