Using traditional methods it takes 92 hours to receive an advanced flying license. A new training technique using Computer Aided Instruction (CAI) has been proposed. A researcher used the technique on 70 students and observed that they had a mean of 93 hours. Assume the population variance is known to be 36. Is there evidence at the 0.05 level that the technique lengthens the training time?
Find the value of the test statistic. Round your answer to two decimal places.
Answer:
The value of the test statistic is z = 1.39.
The p-value of the test is 0.0823 > 0.05, which means that there is not evidence at the 0.05 level that the technique lengthens the training time.
Step-by-step explanation:
Using traditional methods it takes 92 hours to receive an advanced flying license.
This means that at the null hypothesis, it is tested if the mean is of 92, that is:
[tex]H_0: \mu = 92[/tex]
Test if there is evidence that the technique lengthens the training time
At the alternative hypothesis, it is tested if the mean is more than 92, that is:
[tex]H_1: \mu > 92[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
92 is tested at the null hypothesis:
This means that [tex]\mu = 92[/tex]
A researcher used the technique on 70 students and observed that they had a mean of 93 hours. Assume the population variance is known to be 36.
This means that [tex]n = 70, X = 93, \sigma = \sqrt{36} = 6[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{93 - 92}{\frac{6}{\sqrt{70}}}[/tex]
[tex]z = 1.39[/tex]
The value of the test statistic is z = 1.39.
P-value of the test and decision:
The p-value of the test is the probability of finding a sample mean above 93, which is 1 subtracted by the p-value of z = 1.39.
Looking at the z-table, z = 1.39 has a p-value of 0.9177.
1 - 0.9177 = 0.0823.
The p-value of the test is 0.0823 > 0.05, which means that there is not evidence at the 0.05 level that the technique lengthens the training time.
Jessica has 28 coins. One fourth of them are quarters. Two thirds of the rest of the coins are dimes. The remaining ones are nickels. How many quarters, dimes, and nickels does he have? How much money does he have in coins? If he wants to buy 2 packs of cards, with each pack $1.35, how much money would he have left?
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Answer:
7 quarters, 14 dimes, 7 nickels total $3.50$0.80 will remainStep-by-step explanation:
a) 1/4 of 28 = 28/4 = 7 coins are quarters.
2/3 of (28 -7) = (2/3)(21) = 14 coins are dimes
The remaining 28 -7 -14 = 7 coins are nickels
__
b) The amount of money in coins is ...
7×$0.25 +14×$0.10 +7×$0.05 = $3.50 . . . in coins
__
c) 2 packs of cards at $1.35 each will cost 2×$1.35 = $2.70. After the purchase, the remaining money would be ...
$3.50 -2.70 = $0.80 . . . remaining
A distribution of values is normal with a mean of 1986.1 and a standard deviation of 27.2.
Find the probability that a randomly selected value is greater than 1914.8.
P(X> 1914.8) =
Enter your answer as a number accurate to 4 decimal places. *Note: all z-scores must be rounded to
the nearest hundredth.
Answer:
I used the function normCdf(lower bound, upper bound, mean, standard deviation) on the graphing calculator to solve this.
Lower bound = 1914.8Upper bound = 999999Mean = 1986.1Standard deviation = 27.2Input in these values and it will result in:
normCdf(1914.8,9999999,1986.1,27.2) = 0.995621
So the probability that the value is greater than 1914.8 is about 99.5621%
I'm not sure if this is correct 0_o
6. One thousand liters of a solution was available, but the solution was 65% alcohol. Barry needed a solution which was 50% alcohol. How many liters of alcohol had to be extracted so that the solution would be 50% alcohol?
SHOW YOUR WORK
Answer:
300 liters
Step-by-step explanation:
1000(0.65) = 650 liters of the solution was alcohol
1000.(1 - 0.65) = 350 liters was the other solute.
A 50% solution would have equal parts of each or 350 liters each.
650 - 350 = 300 liters of alcohol must be removed.
15.8 Use multiple linear regression to fit x1 0 1 1 2 2 3 3 4 4 x2 0 1 2 1 2 1 2 1 2 y 15.1 17.9 12.7 25.6 20.5 35.1 29.7 45.4 40.2 Compute the coefficients, the standard error of the estimate, and the correlation coefficient.
Answer:
Kindly check explanation
Step-by-step explanation:
regression to fit
x1 0 1 1 2 2 3 3 4 4
x2 0 1 2 1 2 1 2 1 2
y 15.1 17.9 12.7 25.6 20.5 35.1 29.7 45.4 40.2
Using technology ;
The multiple linear regression fit for the data is :
y = 9.025x1 - 5.704x2 + 14.461
Where 9.025 and - 5.704 are the slope values of x1 and x2 respectively.
14.461 = intercept.
The Correlation Coefficient, R from the output is 0.998 ; this depicts a strong positive relationship between the independent variables and dependent variable.
On a map, the scale shown is 1 inch : 5 miles. If an island is 2.5 squire inches on the map, what is the actual area of the island? The actual island's area is square miles.
Answer:
62.5 square miles
Step-by-step explanation:
if the scale is 1 in. = 5 mi, then 1 square in. = 25 square miles
so if 1 in^2 = 25 mi^2
then you make a proportion
25/1 = x/2.5
(the square inches on the bottom and the square miles on top)
solving for x gives you
x=62.5 square miles
Use the graph to complete the statement. O is the origin.
T<2,1> ο r(90°,O) : (4,-1)
Answer:
(3,5)
Step-by-step explanation:
After transformation the point will be (3, 5).
What is a rotation in a transformation ?A rotational transformation can be done clockwise or anticlockwise to certain number of degrees. Rotational transformation does not alter the size and shape of the figure.
Rotating (4,-1) 90° anticlockwise centred at the origin yields the point (1, 4).
Then transforming the point (1, 4) two units to the right and 1 unit up results in the point (3, 5).
We can also rotate 90° clockwise that would result in some different point on this coordinate system.
Instead on a straight line we can also have some 2D figures like a triangle a rectangle etc.
Learns more about Rotational transformation here :
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A baseball is thrown into the air from the top of a 224-foot tall building. The baseball's approximate height over time can be represented by the quadratic equation
MO-167 +800+ 224, where t represents the time in seconds that the baseball has been in the air and represents the baseball's height in feet. When factored, this
equation is -16(-7)(t+ 2).
What is a reasonable time for it to take the baseball to land on the ground?
OA 2 seconds
ОВ
7 seconds
C. 5 seconds
D.
9 seconds
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Answer:
A. 7 seconds
Step-by-step explanation:
We assume your factored equation is something like ...
h(t) = -16t(t -7)(t +2)
The time it takes the ball to reach the ground is the positive value of t that makes a factor zero:
t -7 = 0 ⇒ t = 7
The ball will land on the ground in 7 seconds.
3a + 2b = 9
and
8x + y = 60
(i) What is the value of 9a + 6b?
(ii) What is the value of 4x + 3y?
Answer:
i dont kbow lol gggggggggg
Solve the inequality
Answer:
hope this helps buddy, please mark the brainliest.
Step-by-step explanation:
A cash register contains $10 bills and $50 bills with a total value of $1080.If there are 28 bills total, then how many of each does the register contain?
Answer:
8 ten dollar bills
20 fifty dollar bills
Step-by-step explanation:
x = number of 10 dollar bills
y = number of 50 dollar bills
x+y = 28
10x+50y = 1080
Multiply the first equation by -10
-10x -10y = -280
Add this to the second equation
-10x -10y = -280
10x+50y = 1080
-----------------------
40y = 800
Divide by 40
40y/40 = 800/40
y = 20
Now find x
x+y =28
x+20 = 28
x = 28-20
x= 8
Help once again thanks! !!!!!!!
Two angles of a triangle have the same measure and the third one is 48 degrees greater than the measure of each of the other two. Find the measure of the LARGEST angle in the triangle.
Let the two equal angles each be x
Let the third angle be x + 48
Then ATQ
x + x + x + 48 = 180
3x + 48 = 180
3x = 180 - 48 (Angle Sum Property)
3x = 132
x = 132/3
x = 44
Now the two angles are each 44
And the largest angle = 44 + 48
= 92
Answered by Gauthmath must click thanks and mark brainliest
Largest angle in the triangle is [tex]92^{0}[/tex]
What is triangle?"A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry."
What is angle sum property?"Angle sum property of triangle states that the sum of interior angles of a triangle is 180°."
Let us assume the two equal angles be '[tex]x[/tex]'
According to the question,
Two equal angles = [tex]x[/tex]
Third angle = [tex]x+48^{0}[/tex]
We know the angle sum property
[tex]x+x+x+48^{0} =180^{0}[/tex]
⇒[tex]3x+48^{0}=180^{0}[/tex]
⇒[tex]3x=180^{0}-48^{0}[/tex]
⇒[tex]x=\frac{132^{0} }{3}[/tex]
⇒[tex]x=44^{0}[/tex]
Two equal angles [tex]x[/tex] = [tex]44^{0}[/tex]
Largest Angle = [tex]44^{0} +48^{0}[/tex]
∴ Largest Angle = [tex]92^{0}[/tex]
Hence, Largest Angle = [tex]92^{0}[/tex]
Learn more about triangle and angle sum property here
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4 football is kicked with a speed of 18.0 m/s at an angle of 36.9to the horizontal. 8. How long is the football in the air? Neglect air resistance. A ) 1.1 s B C ) 2.2 D) 3.3 E) 4.0
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Answer:
C) 2.2 seconds
Step-by-step explanation:
The initial vertical speed of the football is ...
v = (18.0 m/s)sin(36.9°) ≈ 10.807 m/s
Since the ball starts and ends at ground level, its speed when it hits the ground is the same as its launch speed. That is, the acceleration due to gravity causes the velocity to change from +v to -v. The time required to do that is ...
t = 2v/g = 2(10.807 m/s)/(9.8 m/s^2) = 21.614/9.8 s ≈ 2.206 s
The football is in the air about 2.2 seconds.
A farmer plants the same amount every day, adding up to 2 1/4 acres at the end of the year. If the year is 3/4 over, how many acres has the farmer planted?
Answer:
9/4 * 3/4 = 27/16 = 1 [tex]\frac{9}{16}[/tex]
Step-by-step explanation:
How many 4-digit passcodes can be created if each digit can be any number, 0-9?
6,561
10,000
40
5,040
Answer:
6,561
that's a good number
0 thru 9 is 10 numbers.
Each digit can be 1 of 10 numbers:
Total combinations = 10 x 10 x 10 x 10 = 10,000
Answer: 10,000
write your answer as an integer or as a decimal rounded to the nearest tenth
Answer:
VW ≈ 4.0
Step-by-step explanation:
Using the sine ratio in the right triangle
sin35° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{VW}{VX}[/tex] = [tex]\frac{VW}{7}[/tex] ( multiply both sides by 7 )
7 × sin35° = VW , then
VW ≈ 4.0 ( to the nearest tenth )
5 năm trước tổng số tuổi của hai mẹ con là 55 tuổi. Hiện nay tuổi con bằng 4/9 lần tuổi mẹ. Tính số tuổi của mẹ và tuổi con hiện nay?
Answer:
12
Step-by-step explanation:
12
If f(x) = 5x - 1, then f^-1(x)=
Answer:
[tex]f^{-1}[/tex](x) = [tex]\frac{x+1}{5}[/tex]
Step-by-step explanation:
let y = f(x) and rearrange making x the subject , that is
y = 5x - 1 ( add 1 to both sides )
y + 1 = 5x ( divide both sides by 5 )
[tex]\frac{y+1}{5}[/tex] = x
Change y back into terms of x , with x = [tex]f^{-1}[/tex] (x) , then
[tex]f^{-1}[/tex] (x) = [tex]\frac{x+1}{5}[/tex]
give that 1/x+2/y=1/2, express y in terms of x and 2
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Answer:
y = 4x/(x -2)
Step-by-step explanation:
Subtract 1/x
2/y = 1/2 -1/x
Combine terms
2/y = (x-2)/(2x)
Cross multiply
4x = y(x -2)
Divide by the coefficient of y
y = 4x/(x -2) . . . . simplest
y = 2^2/(x -2) . . . . in terms of x and 2
what is the least common multiple between 25 and 8
Answer:
200
Step-by-step explanation:
Break down 25 = 5*5
Break down 8 = 2*2*2
They have no common factors
The least common multiple is
5*5*2*2*2 = 25*8 = 200
Answer:
200
Step-by-step explanation:
list the factors of 25: 5,5
factors of 8:2,2,2,
The time it takes me to wash the dishes is uniformly distributed between 8 minutes and 17 minutes.
What is the probability that washing dishes tonight will take me between 14 and 16 minutes?
Give your answer accurate to two decimal places.
The time it takes to wash has the probability density function,
[tex]P(X=x) = \begin{cases}\frac1{17-8}=\frac19&\text{for }8\le x\le 17\\0&\text{otherewise}\end{cases}[/tex]
The probability that it takes between 14 and 16 minutes to wash the dishes is given by the integral,
[tex]\displaystyle\int_{14}^{16}P(X=x)\,\mathrm dx = \frac19\int_{14}^{16}\mathrm dx = \frac{16-14}9 = \frac29 \approx \boxed{0.22}[/tex]
If you're not familiar with calculus, the probability is equal to the area under the graph of P(X = x), which is a rectangle with height 1/9 and length 16 - 14 = 2, so the area and hence probability is 2/9 ≈ 0.22.
Richard is asked to spray wash the exterior of a building that is shaped like a cube. The building has a side length of 7 meters. How much surface area will Richard have to clean?
7 meters squared.
245 meters squared.
49 meters squared.
294 meters squared.
Answer:
294 meters squared
Step-by-step explanation:
Surface area of cube is calculated using the formula :
Surface area of cube = 6a²; where a = side length of the cube
The side length of the cube, a = 7 meters
Hence,
Surface area = 6 * 7² = 6 * 49
Surfave area of cube = 294 meters
Answer:
245 meters squared (correct on my test)
Step-by-step explanation:
Remember, in this case, we complete the formula and then subtract the area of the base. Therefore, we take 6 x (7 meters)^2 and subtract (7 meters)^2. This can also be represented as 5 x (7 meters)^2.
Solve the following equation for n. Be sure to take into account whether a letter is capitalized or not.
t=n-r
Hi there!
»»————- ★ ————-««
I believe your answer is:
[tex]n = t + r[/tex]
»»————- ★ ————-««
Here’s why:
⸻⸻⸻⸻
[tex]\boxed{\text{Solving for 'n'...}}\\\\t = n - r\\----------\\\rightarrow t + r = n -r + r\\\\\rightarrow t+r = n\\\\\rightarrow \boxed{n=t+r}[/tex]
⸻⸻⸻⸻
»»————- ★ ————-««
Hope this helps you. I apologize if it’s incorrect.
Consider points a, b, and c in the graph. Determine which of these points is relative maxima on the interval x = –1 and x = 2 in the graph.
Given:
The graph of a function is given.
To find:
The point that is the relative maxima on the interval x = –1 and x = 2 in the graph.
Solution:
Relative maxima: It is the maximum point of a function over a short interval.
From the given graph it is clear that the graph of the function over the interval x = –1 and x = 2 has a relative maxima at (0,0).
Clearly, (0,0) is represented by point a.
So, the point a is the relative maxima on the interval x = –1 and x = 2 in the graph.
Therefore, the correct option is A.
If there are12 books on a rack,a person has to choose 5books.
In how many ways can he choose if one particular book is always selected?
Answer:
330
11 choose 4
[tex]=\frac{11!}{4!\left(11-4\right)!}\\= 330[/tex]
Step-by-step explanation:
Hi.
• Easy question.
• No Copy paste
1) 40 + 5 × 5 =
Note : actually i come from another country •-•
Answer:
65
Step-by-step explanation:
40 + 5 × 5
40 + 25
65
Good Luck!Note: I also come from another country •-•
[tex]{ \boxed {\huge{ \sf{ \color{blue}{answer : }}}}}[/tex]
65
Step-by-step explanation:
= 40 + 5 × 5
= 40 + 25
= 65
-
#Good_LuckThe tree diagram below shows the possible combinations of juice and snack that can be offered at the school fair.
A tree diagram. Orange branches to popcorn and pretzels. Grape branches to popcorn and pretzels. Apple branches to popcorn and pretzels. Grapefruit branches to popcorn and pretzels.
How many different combinations are modeled by the diagram?
6
8
12
32
Answer:
B. 8Step-by-step explanation:
The combinations are:
Orange - 2 (with popcorn and pretzels)Grape - 2 (with popcorn and pretzels)Apple - 2 (with popcorn and pretzels)Grapefruit - 2 (with popcorn and pretzels)Total number of combinations:
4*2 = 8Correct choice is B
there are 8different combinations are modeled by the diagram.
Answer:
Solution given:
orange:2
grape:2
apple:2
grapefruit:2
no of term:4
now
total no. of combination ia 4*2=8
express the following in standard form (0.000000045)^4
0.00000004 to the power of 4
Your answer would be 0
the value of 5/121^1/2
Answer:
√5/121
Step-by-step explanation:
formula: a^½=√a
(⁵/¹²¹)^½=√⁵/¹²¹
