Answer:
(1,36)(1,36)
Step-by-step explanation:
Suppose that a company claims that its batteries last 240 hours on average.
It took many large samples, and each time the mean number of hours was
outside the 95% confidence interval. Based on this information alone, which
of the following is probably not the mean number of hours that the company's
batteries last?
A. 235
B. 240
C. 230
D. 225
help asap
Answer:
The answer is option B. 240
An ecologist is examining whether the number of fish caught in a large river basin has changed since a fire burned some of the surrounding forested area and vegetation along the river. Data in the form of fishing reports was available for a five-year period before the fire. From a random sample of 195 fishing reports before the fire, the mean catch was 6.3 fish with a standard deviation of 1.6. In a random sample of 143 reports three years after the fire, the mean catch was 7.1 fish with a standard deviation of 2.1.
Required:
What represents the standard error of the difference in the mean number of fish caught before and after the fire?
Answer:
The standard error of the difference in the mean number of fish caught before and after the fire is 0.2153.
Step-by-step explanation:
Subtraction of normal variables:
When we subtract two normal variables, the standard deviation is the square root of the sum of variances of each variable.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Sample of 195 fishing reports before the fire, the mean catch was 6.3 fish with a standard deviation of 1.6.
The standard error for this sample is:
[tex]s_b = \frac{1.6}{\sqrt{195}} = 0.1246[/tex]
Sample of 143 reports three years after the fire, the mean catch was 7.1 fish with a standard deviation of 2.1.
The standard deviation for this sample is:
[tex]s_a = \frac{2.1}{\sqrt{143}} = 0.1756[/tex]
What represents the standard error of the difference in the mean number of fish caught before and after the fire?
[tex]s = \sqrt{s_a^2 + s_b^2} = \sqrt{0.1756^2 + 0.1246^2} = 0.2153[/tex]
The standard error of the difference in the mean number of fish caught before and after the fire is 0.2153.
Answer:
sqrt [ (1.6^2)/195 + (2.1^2)/143 ]
What is the lateral surface area of this net
Help!!!
9514 1404 393
Answer:
720 square feet
Step-by-step explanation:
The lateral area is the area of the central rectangle of the net. It is 12+12+12 = 36 feet long and 20 ft wide.
The lateral area is (36 ft)(20 ft) = 720 ft².
Select all the expressions that have the same value
so what was the question again?
Answer:
Step-by-step explanation:
HELP ME PLS ITS URGENT .. !❗❗❗❗❗❗❗❗❗❗❗❗❗
The commuting distances, in miles, of 10 employees were used to make the box plot shown above. Which of the sets of distances below matches the given box plot?
A.
Commuting Distances: 10, 15, 15, 20, 20, 20, 30, 30, 45, 45
B.
Commuting Distances: 10, 15, 15, 20, 20, 30, 30, 30, 45, 45
C.
Commuting Distances: 10, 15, 20, 20, 20, 20, 30, 30, 45, 45
D.
Commuting Distances: 10, 15, 15, 20, 20, 20, 30, 45, 45, 45
Answer:
A the answer is A ^w^ hope this helps
SOMEONE HELP ME PLEASE!!!!?
Answer:
139
Step-by-step explanation:
supplementary angles add up to equal 180
so to find the measure of angle ABC we subtract the given angle from 180
180-41=139
so we can conclude that angle ABC= 139
Step-by-step explanation:
< ABC and < CBD are supplementary angles.
< CBD = 41°
< ABC + < CBD = 180° ( Being supplementary angles)
< ABC + 41° = 180°
< ABC = 180° - 41°
< ABC = 139°
Hope it will help :)❤
Help..................
Calculate the SQRT485 Express answer to nearest hundredth.
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Answer: 22.02
Explanation:
I hope this helped!
<!> Brainliest is appreciated! <!>
- Zack Slocum
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
what is the volume of the cylinder?
A:703.2ft3
B:50.2ft3
C:602.9ft3
D: 653.1ft3
Quadrilateral A'B'C'D' Is the image of quadrilateral ABCD under a dilation.
What is the scale factor of the dilation?
Answer:
Scale factor = [tex]\frac{1}{4}[/tex]
Step-by-step explanation:
Formula for the dilation to be used,
Scale factor = [tex]\frac{\text{Dimension of the image}}{\text{Dimension of the original}}[/tex]
= [tex]\frac{A'B'}{AB}[/tex]
= [tex]\frac{1}{4}[/tex]
Therefore, scale factor by which quadrilateral ABCD has been dilated to form image quadrilateral A'B'C'D' is [tex]\frac{1}{4}[/tex].
What is the slope of the line below?
(1-2)
(
4-2)
A. negative
B. undefined
C. positive
D. Zero
Answer: D. Zero
Step-by-step explanation:
It’s a flat line. Flat horizontal lines are ALWAYS zero
Round 7.54 please I need help
WILL MARK B!
Please I need help I have a quiz
Answer:
a) 2x² - x + 3 = x(2x + 1) - 2x
<=> 2x² - x + 3 = 2x² + x - 2x
<=> 3 - x = - x
<=> 3 = 0
=> no solution
b) x/2 - x/3 - x/4 = 1/12
[tex] \frac{6x}{12} - \frac{4x}{12} - \frac{3x}{12} = \frac{1}{12} \\ \\ \frac{ - x}{12} = \frac{1}{12} \\ \\ = > - x = 1 \\ \\ \\ < = > x = 1[/tex]
=> the euqation has the solution x = 1
c) |x - 5| = 2|x|
=> x - 5 = 2x
or x - 5 = -2x
<=> x = -5
or 3x = 5
<=> x = -5
x = -5or x = 5/3
d) defined conditions: 2 - x 》 0
<=> x 《 2
we have:
[tex] \sqrt{x + 4} = 2 - x \\ < = > x + 4 = (2 - x) {}^{2} \\ < = > x + 4 = {x}^{2} - 4x + 4 \\ < = > {x}^{2} - 5x = 0 \\ < = > x(x - 5) = 0 \\ [/tex]
<=> x = 0 (because x 《 2)
e)
[tex] \sqrt{5} = \frac{1}{25 {}^{x} } \\ = > 5 = \frac{1}{25 {}^{2x} } \\ < = > 5.25 {}^{2x} = 1 \\ < = > 5.5 {}^{4x} = 1 \\ < = > 5 {}^{4x + 1} = 1 \\ = > 4x + 1 = 0[/tex]
<=> x = -1/4
Answer:
[tex]a) [x: - \infty < x < \infty ][/tex]
[tex]b)[x: - 1][/tex]
[tex]c) [x:- \frac{5}{3} ][/tex]
[tex]d) [x: 3, 0][/tex]
[tex]e) [x: - \frac{1}{4} ][/tex]
If John gets paid $45.00 an hour and works 10 hours, how much does he earn?
8. Determine the area of a sector
with a central angle of 42° in a
circle with radius 3 inches.
NEED IT ASAP
Answer:
[tex]\boxed {\boxed {\sf A \approx 3.3 \ in^2}}[/tex]
Step-by-step explanation:
Since we are given the central angle in degrees, we should use the following formula for sector area.
[tex]A= \frac {\theta}{360}* \pi r^2[/tex]
The angle is 42 degrees and the radius is 3 inches. Therefore,
[tex]\theta= 42 \\r=3 \ in[/tex]
[tex]A=\frac {42}{360} * \pi (3 \ in)^2[/tex]
Solve the exponent.
(3 in)²= 3 in*3in = 9 in²[tex]A=\frac {42}{360} * \pi (9 \ in^2)[/tex]
Multiply all three numbers together.
[tex]A= 0.116666666667* 3.14159265359 * 9 \ in^2[/tex]
[tex]A=3.29867228627 \ in^2[/tex]
Let's round to the tenth place. The 9 in the hundredth place tells us to round the 2 up to a 3.
[tex]A \approx 3.3 \ in^2[/tex]
The area of the sector is approximately 3.3 square inches.
Asha is tiling the lobby of the school with one-foot square tiles. She has 6 bags
of tiles with 50 tiles in each. The lobby is a 30-foot by 8-foot rectangle. How
many tiles will Asha have left over after she tiles the lobby?
Answer:
60 tiles left over
Step-by-step explanation:
the lobby needs 30 x 8 = 240 tiles.
she has 6 x 50 = 300 tiles
300 - 240 = 60 left over
The difference of two numbers is 14.Twice the smaller is 6 more than the larger.Find the numbers.
A pizza pan is removed at 9:00 PM from an oven whose temperature is fixed at 450°F into a room that is a constant 70°F. After 5 minutes, the pizza pan is at 300°F.
(a) At what time is the temperature of the pan 125°F?
(b) Determine the time that needs to elapse before the pan is 150°.
(c) What do you notice about the temperature as time passes?
Answer:
A) It will get to a temperature of 125°F at 9:19 PM
B) It will get to a temperature of 150°F at 9:16 PM
C) as time passes temperature approaches the initial temperature of 450°F
Step-by-step explanation:
We are given;
Initial temperature; T_i = 450°F
Room temperature; T_r = 70°F
From Newton's law of cooling, temperature after time (t) is given as;
T(t) = T_r + (T_i - T_r)e^(-kt)
Where k is cooling rate and t is time after the initial temperature.
Now, we are told that After 5 minutes, the temperature is 300°F.
Thus;
300 = 70 + (450 - 70)e^(-5k)
300 - 70 = 380e^(-5k)
230/380 = e^(-5k)
e^(-5k) = 0.6053
-5k = In 0.6053
-5k = -0.502
k = 0.502/5
k = 0.1004 /min
A) Thus, at temperature of 125°F, we can find the time from;
125 = 70 + (450 - 70)e^(-0.1004t)
125 - 70 = 380e^(-0.1004t)
55/380 = e^(-0.1004t)
In (55/380) = -0.1004t
-0.1004t = -1.9328
t = 1.9328/0.1018
t ≈ 19 minutes
Thus, it will get to a temperature of 125°F at 9:19 PM
B) Thus, at temperature of 150°F, we can find the time from;
150 = 70 + (450 - 70)e^(-0.1004t)
150 - 70 = 380e^(-0.1004t)
80/380 = e^(-0.1004t)
In (80/380) = -0.1004t
-0.1004t = -1.5581
t = 1.5581/0.1004
t ≈ 16 minutes.
Thus, it will get to a temperature of 150°F at 9:16 PM
C) As time passes which means as it approaches to infinity, it means that e^(-kt) gets to 1.
Thus,we have;
T(t) = T_r + (T_i - T_r)
T_r will cancel out to give;
T(t) = T_i
Thus, as time passes temperature approaches the initial temperature of 450°F
3 |a| +5 |b| if a = −2; b = −1
WILL AWARD BRAINLIEST
Answer:
-11
Step-by-step explanation:
[tex]3( - 2) + 5( - 1)[/tex]
[tex] - 6 + ( - 5)[/tex]
[tex] - 11[/tex]
ik this is alot but please help me.
Answer:
help u in what please ask the question so we can anwser
A number greater than or equal to 41.
Answer:
42
Step-by-step explanation:
¯\_(ツ)_/¯
The remaining questions refer to the following situation: Suppose a certain farmer wants to find out if the average length of the green beans in her field is 4 inches. She collects a random sample of 100 beans and get a sample mean of 3.75 inches. (Suppose she knows that the population standard deviation of bean length is 0.5.) What is the population in this situation
Answer:
The population in this situation is all green beans in her field.
Step-by-step explanation:
Informally, if you take a sample of an object, the population in all of these objects.
In this question:
Sample of 100 green beans in her field. This means that the population in this situation is all green beans in her field.
The inequality x < 15 can be used to represent how tall a tree is, where x is it’s height in feet. Which of these statements best describes how tall the tree is
Answer:
The tree is less than 15 feet
Step-by-step explanation:
Given
[tex]x < 15[/tex]
Required
Interpret
The above inequality implies that the value of x is less than 15.
Since x represents the height of the tree in feet.
We can say that:
The tree is less than 15 feet
What number divided by 4 equals 6?
Type the correct answer, then press Enter.
Answer:
24
Step-by-step explanation:
Let x be the number.
[tex]x/4=6[/tex]
Multiply both sides by 4 to isolate x
[tex](x/4)4=6*4\\x=24[/tex]
I hope this helps!
If the scale factor of Figure A to Figure B is 7:2 find the perimeter of Figure A.
lol plss we did this literally a week ago and I forgot how to do it
Answer:
okay so i believe its area (if its not ill comment the right answer) so you just do the height (12) times the length (12) giving you 144
Step-by-step explanation:
dilation of 1.5 about the origin
Answer:
Step-by-step explanation:
use the rule they tell you of 1.5
so (x,y) ⇔1.5(x,y)
w = (2,0)
x = ( 0,2)
y = (-2, 1)
z = (0, -2)
1.5(x,y)
W' = (3,0)
X'= (0, 3)
Y' = ( -3, 1.5)
Z' = (0, -3)
nice :)
45,678 in unit form
a pet shop sells a 6 can multipack of dog food for £3.18 and a 15 can multipack for £7.80. which multipack is the best value for money
Answer:
the 15 multi pack
Step-by-step explanation:
Could someone help me with with 6-10??
Answer:
You need a protractor
Step-by-step explanation:
to measure the angles