The lifetime of a certain brand of battery is known to have a standard deviation of 9 hours. Suppose that a random sample of 90 such batteries has a mean lifetime of 38.9 hours. Based on this sample, find a 90% confidence interval for the true mean lifetime of all batteries of this brand.
Answer:
lower limit : 36.44
upper limit : 39.56
Step-by-step explanation:
Given :
s = 9
n = 90
x = 38.9
Alpha, α = 0.10
∴ [tex]$z_{\alpha/2}=z_{0.05} = 1.645$[/tex]
The confidence interval is :
[tex]$=x \pm\left(z_{\alpha /2} \times \frac{s}{\sqrt{n}}\right)$[/tex]
[tex]$=38.9 \pm\left(1.645 \times \frac{9}{\sqrt{90}}\right)$[/tex]
[tex]$=38.9 \pm 1.56$[/tex]
[tex]$=(36.44, 39.56)$[/tex]
Therefore,
lower limit : 36.44
upper limit : 39.56
hi can someone help me w this
Answer:
336 ft³ or 336 cubic feet
Step-by-step explanation:
Volume = Area triangle * height
Area triangle = 1/2(8 x 14)
Area triangle = 1/2(112) = 56 ft²
56 ft² * 6 ft = 336 ft³
If my answer is incorrect, pls correct me!
If you like my answer and explanation, mark me as brainliest!
-Chetan K
Let g(x) be the transformation of f(x)= 3x - 5 when it is translated 6 units up followed by a horizontal stretch by a factor of 3/2.
g(x) = Blank 1X +Blank 2
Answer:
g(x) = 2x + 1
Step-by-step explanation:
f(x)= 3x - 5 when it is translated 6 units up
Translating a function a units is adding a to the function. So
[tex]3x - 5 + 6 = 3x + 1[/tex]
Horizontal stretch by a factor of 3/2.
This means that [tex]g(x) = f(\frac{2x}{3})[/tex], that is. So
[tex]g(x) = 3(\frac{2x}{3}) + 1 = 2x + 1[/tex]
Then
g(x) = 2x + 1
2x - y - 4 = 0
3x + y - 9 = 0
What is the solution set of the given system?
Answer:
[tex](\frac{13}{5};\frac{6}{5}).[/tex]
Step-by-step explanation:
[tex]1)\left \{ {{5x=13} \atop {y=2x-4}} \right. \ 2)\left \{ {{x=\frac{13}{5} } \atop {y=\frac{6}{5} }} \right.[/tex]
short explanation: 1) to add the 1st equation to the 2d; 2) to calculate the value of 'x', then to substitute x=13/5 into the 2d equation and calculate the value of 'y'.
It is reported in USA Today that the average flight cost nationwide is $445.99. You have never paid close to that amount and you want to perform a hypothesis test that the true average is actually greater than $445.99. What are the appropriate hypotheses for this test
Answer:
[tex]H_0[/tex] : [tex]\mu \leq 445.99[/tex]
[tex]H_a[/tex] : [tex]\mu > 445.99[/tex]
Step-by-step explanation:
It is given the average cost of the flight nationwide is $ 445.99
I wanted to [tex]\text{perform the hypothesis test}[/tex] to determine that the true average is greater than $ 445.99
Let the hypothesis that the true average is actually greater than $445.99
Therefore,
the [tex]\text{null hypothesis}[/tex] for the test is :
[tex]H_0[/tex] : [tex]\mu \leq 445.99[/tex]
And the alternate hypothesis is :
[tex]H_a[/tex] : [tex]\mu > 445.99[/tex]
Will pick brainliest. How would I do this?
Undefined
Order of matrix Q is 4 by 3
whereas order of R is 4by 4
In order to add two matrices , they should be of same order.
Answer:
DOES NOT EXIST.
Step-by-step explanation:
The sum of two matrices exists only if the matrices are of the same order.
Here Q is 3x3 and R is 4x4, so they do not have the same order, hence the sum DOES NOT EXIST.
HELP ME WITH THIS PLSSS!!!
A circle has been divided into three equal angles. is each angle acute obtuse or right?
Answer:
obtuse
Step-by-step explanation:
A circle is 360 degrees
Divide by 3
360/3 =120
This is greater than 90 and less than 180 so it is obtuse
what are the multiples of 5 between 61 and 69
Answer:
I think it is 65 because we can divide it by 5
Answer:
i think there is only one multiple which is 65
Please! Help, Also please show you’re work! will give brainliest to all who gives me the best answer
Answer:
Hope this helps. If it doesn't then I apologize.
Mrs Gren baked a cake on her son's birthday and divided it into 12 pieces.
Serah
ate 1/3 of the cake and her son ate 1/4 of the cake.
2. How many pieces of the cake did Serah eat?
- How many pieces of the cake did her son eat?
What fraction of the cake was eaten?
What fraction of the cake was left?
Answer:
2
Step-by-step explanation:
it has 2 in the equation
Make use of the given interpretation for the median to assign probabilities to the simple events and find P(A), P(B), and P(C).
Answer: Hello your question is incomplete below is the missing part of the question
The Bureau of the Census reports that the median family income for all families in the United States during the year 2003 was $43,318. That is, half of all American families had incomes exceeding this amount, and half had incomes equal to or below this amount. Suppose that four families are surveyed and that each one reveals whether its income exceeded $43,318 in 2003.
answer :
P(A) = 11 / 16
P(B) = 3/8
and P(C) = 1/4
Step-by-step explanation:
Making use of the given interpretation for the median we can assign probabilities to simple events as
P(A) = | A | / | sample space |
where | A | = 11
sample space = 16
P(A) = 11 / 16
∴ P(B) = 6/16 = 3/8
and P(C) = 4/16 = 1/4
1
5. Monica put $600 in a savings account that pays an interest rate of 3.5%.
She collected $120 in interest
Answer:
pls complete your question. what exactly are we supposed to calculate?
Kate leans a ladder against her house to get to the roof. The house is 25 feet tall and The ladder is 15 feet away from the side of the house. What is the angle that the latter makes with the ground?
Answer:
this is the correct answer
please mark brainliest
a tree is standing 35 feet high. tom is attempting to align a 40 foot ladder to the tree to get his cat out. find the angle that the ladder will make with the ground.
Answer:
61º
Step-by-step explanation:
sin= opp/hyp
sin∅ = 35/40
∅ = arcsin35/40
use calculator
∅ = 61.044975628140152
∅ ≈ 61º
A coffee distributor needs to mix a(n) Mexican Shade Grown coffee blend that normally sells for $8.10 per pound with a Tanzanian coffee blend that normally sells for $14.10 per pound to create 100 pounds of a coffee that can sell for $10.26 per pound. How many pounds of each kind of coffee should they mix?
Answer:
64 pounds of the $8.10 Mexican Shade Grown
36 pounds of the $14.10 Tanzanian
Step-by-step explanation:
8.1x + 14.1(100 - x) = 10.26(100)
Distribute
8.1x + 1410 - 14.1x = 1026
Combine like terms
1410 - 6x = 1026
Subtract 1410 from both sides
-6x = -384
Divide both sides by -6
x = 64 pounds of the $8.10
100 - x = 36 pounds of the $14.10
Question 2.1
Solve the following problem. Round to one decimal place if
necessary. If your answer is correct you will see an image
appear on your screen.
Answer:
x = 5.3
Step-by-step explanation:
Reference angle (θ) = 24°
Opposite side to the reference angle = x
Adjacent side = 12
Apply TOA, which is:
Tan θ = Opp/Adj
Plug in the values
Tan 24° = x/12
12*Tan 24° = x
5.34274422 = x
x = 5.3 (approximated to one decimal place)
please help me i’m begging!!
i need to match them
An angle of depression is measured from the horizon downwards and an angle of elevation is measured from the horizon upwards.
When solving for the sides or angles of a right triangle you can use trigonometry. The sine of an angle is found by the ratio of the opposite side and the hypotenuse. The cosine of an angle is found by the ratio of the adjacent side and the hypotenuse. The tangent of an angle is found by the ratio of the opposite side and the adjacent side.
The opposite side is always the leg opposite the angle that you are using. The adjacent side is the leg that forms one of the sides of the angle you are talking about and the hypotenuse is always across from the right angle.
If you know two lengths you can find the third leg length by using the Pythagorean Theorem.
Drag each value to the correct location on the box plot. Not all values will be used.
The heights, in centimeters, of 10 students are given in the table.
160
159
158.5 168
162
164.5
164
169
161
160.5
Sam creates a box plot for this data. Match the values to the correct locations on theplot.
169
161.5
160
159
162
164.5
168
158.5
Answer:
PUT THEM IN ORDER SO I CAN UNDERSTAND oh 56.86
double a number equals 18 help pls
Answer:
9 is the answer
Answer:
2n=18
Step-by-step explanation:
Double means multiply by 2. A number can be represented by n.
So the equation is
2n=18
BONUS:
2n=18
/2 /2
n=9
---
hope it helps
Find the value of x to the nearest tenth.
Step-by-step explanation:
p^2+b^2=h^2
or, 16+9=h^2
or, 25=h^2
or h=5
again, p^2 +b^2=h^2
or, 25+b^2=36
or, b^2=11
or. b=√11 therefore b=x=√11
tv originally cost $400 if the price of the TV increase by 15% what is the new price
Answer:
$460
Step-by-step explanation:
Thus, a product that normally costs $400 with a 15 percent discount will cost you $340.00, and you saved $60.00. You can also calculate how much you save by simply moving the period in 15.00 percent two spaces to the left, and then multiply the result by $400 as follows: $400 x .15 = $60.00 savings.
I NEED HELP PLZ THIS JS MY LAST QUESTION WILL MARL YOU
Answer:
-4
Step-by-step explanation:
60 + x + 124 = 180 degree (being linear pair)
x + 184 = 180
x = 180 - 184
x = -4
Answer:
x+124=180(linear pair angle)
x=56
i am confused between -4 and 56
The sum of two numbers is 90 and their ratio is 1/5.
What is the difference between the largest and the smallest of the two numbers?
a. 15
b. 18
c. 60
d. 75
e. 45
Answer:
C. 60
Step-by-step explanation:
1+5=6
90÷6=15
15 ×5=75
15×1=15
75-15=60
The difference between the largest and the smallest of the two numbers is 60.
We have given that,
The sum of two numbers is 90 and their ratio is 1/5.
What is the difference?
The difference is a key concept of philosophy, denoting the process or set of properties by which one entity is distinguished from another within a relational field or a given conceptual system
[tex]1+5=6\\90\6=15\\15 \times 5=75\\15\times 1=15\\75-15=60[/tex]
Therefore, The difference between the largest and the smallest of the two numbers is 60.
To learn more about the difference visit:
https://brainly.com/question/148825
#SPJ2
A consumer advocacy group is doing a large study on car rental practices. Among other things, the consumer group would like to estimate the mean monthly mileage, , of cars rented in the U.S. over the past year. The consumer group plans to choose a random sample of monthly U.S. rental car mileages and then estimate using the mean of the sample. Using the value miles per month as the standard deviation of monthly U.S. rental car mileages from the past year, what is the minimum sample size needed in order for the consumer group to be confident that its estimate is within miles per month of
Answer:
The minimum sample size needed 64 monthly U.S. rental car mileages.
Step-by-step explanation:
Note: This question is not complete as all the important data are omitted. The complete question is therefore provided before answering the question as follows:
A consumer advocacy group is doing a large study on car rental practices. Among other things, the consumer group would like to estimate the mean monthly mileage, u, of cars rented in the U.S. over the past year. The consumer group plans to choose a random sample of monthly U.S. rental car mileages and then estimate u using the mean of the sample. Using the value 850 miles per month as the standard deviation of monthly U.S. rental car mileages from the past year, what is the minimum sample size needed in order for the consumer group to be 95% confident that its estimate is within 175 miles per month of u?
The explanation of the answer is now given as follows:
The minimum sample size needed can be calculated using the following sample size formula:
n = ((Z * S) / E)^2 ………………………… (1)
Where:
n = sample size or minimum sample size = ?
Z = Confidence interval at 95% = 1.645
S = Standard deviation = 850
E = Accepted magnitude of error = 175
Substituting all the relevant values into equation (1), we have:
n = ((1.645 * 850) / 175)^2 = (1,398.25 / 175)^2 = 7.99^2 = 63.8401, or 64.
Therefore, the minimum sample size needed 64 monthly U.S. rental car mileages.
Use your graph to find estimates of the solutions to the equation x^2-x-6=-2
Answer:
-2 and 3
Step-by-step explanation:
From the graph, the solution is the points where the curve cuts the x axis. From the graph, you can see that the equation cuts the x axis at two points that is at x=-2 and 3.
Hence the solutions to the equation is -2 and 3
A company wants to select 1 project from a set of 4 possible projects. Which of the following constraints ensures that only 1 will be selected?
a. X1 + X2 + X3 + X4 = 1
b. X1 + X2 + X3 + X4 = 1
c. X1 + X2 + X3 + X4= 1
d. X1 + X2 + X3+ X4= 0
Given:
A company wants to select 1 project from a set of 4 possible projects.
Consider the options are:
a. [tex]X_1+X_2+X_3+X_4=1[/tex]
b. [tex]X_1+X_2+X_3+X_4\leq 1[/tex]
c. [tex]X_1+X_2+X_3+X_4\geq 1[/tex]
d. [tex]X_1+X_2+X_3+X_4\geq 0[/tex]
To find:
The constraints that ensures only 1 will be selected.
Solution:
It is given that the company wants to select 1 project from a set of 4 possible projects. It means the sum of selected projects must be equal to 1.
[tex]X_1+X_2+X_3+X_4=1[/tex]
Therefore, the correct option is (a).
he monthly sales of furniture stores in Dubai were collected and summarized. The mean and the median of the monthly sales are 130,000 AED and 170,000 AED respectively. The distribution of the monthly sales is
symmetrical.
none of the above.
positively skewed.
negatively skewed.
Given:
The mean and the median of the monthly sales are 130,000 AED and 170,000 AED respectively.
To find:
The distribution of the monthly sales.
Solution:
We know that,
For symmetrical distribution, mean is equal to median.
For positively skewed distribution, mean is greater than median.
For negatively skewed distribution, mean is less than median.
We have,
Mean of the monthly sales = 130,000 AED
Median of the monthly sales = 170,000 AED
Here, Mean is less than the median because 130,000 < 170,000.
Therefore, the distribution is negatively skewed. Hence, the correct option is D.
The path earth follows around the sun is earth's ___
A translação é o movimento que a Terra realiza em torno do Sol, sendo que ela demora 365 dias, 5 horas e 48 minutos para completá-lo. Esse movimento é o responsável direto pela existência das estações do ano. Como o eixo de inclinação do nosso planeta é de 23º27', há períodos em que os dias são maiores que as noites (solstícios de verão), períodos em que as noites são maiores que os dias (solstícios de inverno) e períodos em que eles possuem a mesma duração (equinócios de primavera e outono).
please answer both thanks
The maximum load that a cylindrical column with a circular cross section can hold varies directly as the fourth power of the diameter and inversely as the square of the height. A 9 meter column 2 meters in a diameter will support 64 metric tons. How many metric tons can be supported by a column 13 meters high and 5 meters in diameter? Round to the nearest whole metric ton
Answer:
2396
Step-by-step explanation:
Let the diameter = d
Let the height = h
Formula
Metric Tons = k * d^4 / h^2
Solution
Metric Tons = 64
d = 2
h = 9
k = ?
(You can't do the second part by not using a ratio unless you put k in and solve for it)
64 = 2^4 k / 9^2
64 = 8 *k / 81
64 * 81 / 8 = k
5184 / 8 = k
k = 648
Solve for the second example
Metric Tons = d^4 * k / h^2
Metric Tons = ?
d = 5
h = 13
k = 648
Metric Tons = 5^4 * 648 / 13^2
Metric Tons = 625 * 648 / 169
Metric Tons = 2396 rounded.