A car rental company is interested in the amount of time its vehicles are out of operation for repair work. A random sample of 21 cars showed that, over the past year, the numbers of days that each of these cars had been inoperative were as follows: 15, 11, 19, 24, 6, 18, 20, 15, 18, 12, 14, 19, 5, 21, 12, 11, 8, 10, 7, 2, 14 Assuming that the population is normally distributed, construct a 95% confidence interval for the mean number of days that vehicles in the company's fleet are out of operation.
Answer:
(10.891; 15.869)
Step-by-step explanation:
Given the data::
15, 11, 19, 24, 6, 18, 20, 15, 18, 12, 14, 19, 5, 21, 12, 11, 8, 10, 7, 2, 14
The confidence interval is obtained using the relation :
Mean ± margin of error
Margin of Error = Zcritical * s/sqrt(n)
Using a calculator, the mean value of the data and standard deviation above is :
Mean = Σx / n ; n = sample size
Mean, xbar = 281 / 21
Mean = 13.38
Standard deviation , s = sqrt[Σ(X - xbar)²/ n-1]
Standard deviation, s = 5.82
Margin of Error = Zcritical * s/sqrt(n)
Zcritical at 95% confidence level = 1.96
Margin of Error = 1.96 * 5.82/sqrt(21) = 2.489
Confidence interval :
Mean ± margin of error
13.38 ± 2.489
Lower boundary = (13.38 - 2.489) = 10.891
Upper boundary = (13.38 + 2.489) = 15.869
(10.891; 15.869)
Simone asked her classmates, "How many days do you floss your teeth in a
typical week?" The table shows Simone's data.
Days of Flossing per Week
6
3
1
4
3
3
5
6
6
7
7
6
5
3
2.
4
0
4.
5
7
1
2
6
7
How many observations did she record?
Answer:
24
Step-by-step explanation:
Count the amount of answers she got.
A set of data is Normally distributed with a mean of 25 and a standard deviation of 5. What percent of values are between the z-values –0.4 and 0.6? Round to the nearest whole percent.
Use the z-table to answer the question.
9%
19%
38%
49%
Answer:
38%
Step-by-step explanation:
Answer:
38% is correct
ED2021
Factor by removing a common
1. 3a +9ab
Answer:
3a(1+3b)
Step-by-step explanation:
First step is to find the greatest common factor between these two terms, which is 3a. Next you'll need to divide the two terms by that factor, which would give you what would be in the parenthesis, placed the factor in front to signify the multiplication of those terms and voila, you got the fully factored form.
Simplify 42 ⋅ 48.
Please help with this!
Answer:
Step-by-step explanation:
a^x. a^y=a^{x+y}
4²*4^8=4^{10}
Answer:
4 to the power of 10
Step-by-step explanation:
Pls help me complet this
Answer:
P(for) = 5/8
P(against) = 3/10
P(undecided)= 3/40
Step-by-step explanation: Again, find the total number of people Devi surveyed.
40 people got surveyed in total. So P(for) means to find how many people wanted to vote for the mayor. In the table, it says 25 voted for the current mayor. So 25/40. Then we can simplify it to 5/8.
Then find how many people voted against her. 12 people voted against her. 12/40 is 3/10.
Finally, find how many people were indecisive. 3 people were indecisive. 3/40. We cannot simplify it, so leave it like that. Hope this helps.
The following data show the average retirement ages for a random sample of workers in the United States and a random sample of workers in Japan. Perform a hypothesis test using α = 0.05 to determine if the average retirement age in Japan is different from the United States. Calculate the test-statistics (round to 3 decimals - report the absolute value).
Answer:
[tex]t \approx 2.639[/tex]
Step-by-step explanation:
Given
[tex]\begin{array}{ccc}{} & {USA\ 1} & {Japan\ 2} & {\bar x} & {64.6} & {67.5} &{n} & {30} & {30} & {\sigma} & {4.0} & {4.5} \ \end{array}[/tex]
See attachment for data
Required
Determine the test statistic
The test statistic is calculated using:
[tex]t = \frac{\bar x_1 - \bar x_2}{\sqrt{\frac{\sigma_1^2}{n_1} + \frac{\sigma_2^2}{n_2}}}[/tex]
So, we have:
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{4.0^2}{30} + \frac{4.5^2}{30}}}[/tex]
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{16.00}{30} + \frac{20.25}{30}}}[/tex]
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{16.00+20.25}{30}}}[/tex]
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{36.25}{30}}}[/tex]
[tex]t = \frac{-2.9}{\sqrt{1.2083}}[/tex]
[tex]t = \frac{-2.9}{1.099}[/tex]
[tex]t \approx -2.639[/tex]
The absolute value is:
[tex]t \approx 2.639[/tex]
An engineer stands 50 feet away from a building with a surveying device mounted on a tripod. if
the surveying device is 5 feet above the ground and the angle of elevation is 50°, find how tall is
the building.
Answer:
The building is 64.6 feet tall.
Step-by-step explanation:
To determine the height of the building, let the height from the top of the building to the top of the tripod be represented by x. So that;
Height of the building = x + 5
But,
Tan θ = [tex]\frac{opposite}{adjacent}[/tex]
Tan [tex]50^{o}[/tex] = [tex]\frac{x}{50}[/tex]
x = 50 x Tan [tex]50^{o}[/tex]
= 50 x 1.1918
= 59.59
x = 59.59
Height of the building = x + 5
= 59.59 + 5
= 64.6 ft
The height of the building is 64.6 feet.
Can someone please help me figure out the costing for the serving on this recipe.
Steps on how is on: wikihow.com/cost-a-recipe
1ч (х – 2) =36 times-Ч2
Answer:
x = -7
Step-by-step explanation:
14(x - 2) = 3(-42)
14x - 28 = -126
14x = -126 + 28
14x = -98
x = -7
find the surface area of the rectangular prism.
A 90 cm2
B 135 cm2
C 225 cm2
D 270 cm2
Answer:
D. 270 cm2
Step-by-step explanation:
2*(15*5 + 15*3 + 5*3) = 270 cm2
*
87-1 = 25+2 simplifies to :
Answer:
175 /2
Step-by-step explanation:
A retiree invests $7,000 in a savings plan that pays 7% per year. What will the account balance be at
the end of the first year?
Answer:
$6510
Step-by-step explanation:
First thing that should come to mind is: What is 7% of $7000?
Well, if you don't know how to find a percent of something, this is the formula you use:
7000 x 0.07 = 490.
In the first year, they will receive 490 out of the 7000 they've invested.
7000 - 490 = 6510.
Therefore, the account balance at the end of the first year will be 6510.
The account balance at the end of first year will be equal to $6510.
What do you mean by percentage ?
Percentage is the relative value indicating one hundredth part of any quantity.
It is given that a retiree invests $7000 in a savings plan which pays 7% per year. So , it meant that we need to calculate that what is the value 7% of $7000.
So , 7% of $7000 is :
= 7000 × [tex]\frac{7}{100}[/tex]
= $490
It is known that this amount is paid as per plan per year. So, to find out the account balance at the end of the first year , we need to subtract the invested amount to the amount per year at 7%.
So , the account balance at the end of first year will be :
= 7000 - 490
= $6510
Therefore , the account balance at the end of first year will be equal to $6510.
Learn more about percentage here :
brainly.com/question/22091903
#SPJ2
Solve for 0 Round your answer to the nearest tenth.
20
13
A =
degrees
Answer:
1.835
Step-by-step explanation:
use pythagoras theorem to find missing side
use sin to find missing angle
missing side/13 = 1.835
What’s the correct answer for this question?
ANSWER
l
Or
Or
EXPLANATION
The given line has slope,
and
We can find the equation in the point slope form, which is given by,
We substitute the point and slope to get,
We can also simplify further to get,
We make y the subject to get,
This is called the slope intercept form.
We could also write in standard form to get
Or
Create an algebraic expression to solve the following problems.
a) Jeff’s cell phone plan charges him $10 per GB with no extra fees. How much will his bill be for 6 GB?
b) Marks cell phone charges him $8 per GB and a monthly fee of $15 how much will his bill be for 10 GB
c) Ricks cell phone plan charges him $5 per GB and a monthly for of $30. How much will his bill be for 2 GB?
PLEASE ANSWER PLEASE
Answer:
Step-by-step explanation:
x is the number of GB
f(x) is the cost in dollars
f(x) = 10x
Bill for 6 GB = f(6) = 60
:::::
f(x) = 8x+15
Bill for 8 GB = f(10) = 95
:::::
f(x) = 5x+30
Bill for 2 GB = f(2) = 40
BRAINLIEST FOR ALL 3 CORRECT ANSWERS, IM FAILING SCHOOL AND NEED HELP ASAP. EVEN OFFICIAL HELP COUNTS
Answer:
1. quarter turn 2. B 3. (b,-a)
Step-by-step explanation:
PLS ANSWER QUICK, HELP
Answer:
1014 in
Step-by-step explanation:
(13 x 13) x 6 = 1014 in^3
Answer:
The answer should be A (676)
Step-by-step explanation:
How to do subtract 1.7 from 3 show your work
192, 96, 48, 24 what are the next three terms
Answer:
12,6,3
Step-by-step explanation:
its dividing by half
13. Describe and correct the error in finding the product.
X (x – 5)² = x² – 52
= x2 - 25
Answer:
Answer:
x=−1.27794
Step-by-step explanation:
x(x−5)2=x2−52
x3−10x2+25x=x2−52
Step 1: Subtract x^2-52 from both sides.
x3−10x2+25x−(x2−52)=x2−52−(x2−52)
x3−11x2+25x+52=0
Step 2: Use cubic formula.
x=−1.27794
Hope it helps +_+
Il means
* is equal to
* is parallel to
*lines
* therefore
* none of these
Pioneer company has given an aptitude test to 71 potential job applicants. The test score had an average of 81 and a standard deviation of 8. Aptitude tests are known to follow a t-distribution. Pioneer rejects the bottom 5% of the applicants right away. The top 5% are hired immediately at managerial positions.
A. What is the degrees of freedom for this distribution?
B. What is the t-score for someone who has scored 93?
C. What is the cutoff score for those who'll be hired as managers?
D. What will be the cutoff score fro those who'll get rejected right away?
E. If we want to define the middle of the class (80%) to be average, what will be the lower cut-off scores?
F. If we want to define the middle of the class (80%) to be average, what will be the upper cut-off scores?
Answer:
Follows are the solution to the given points:
Step-by-step explanation:
In point A:
[tex]\to df = n - 1 = 71-1= 70[/tex]
In point B:
[tex]\to t = \frac{(x -X)}{s} = \frac{(93-81)}{8} = \frac{12}{8}= 1.5[/tex]
In point C:
For df = 70, the top 5% critical t score
tcrit = 1.666914479
Thus,
[tex]\to 1.666914479 = \frac{(x - 81)}{8}\\\\\to 1.666914479 \times 8 = (x - 81)\\\\\to 13.335315832 = (x - 81)\\\\\to 13.335315832 +81 =x \\\\\to x= 94.335315832[/tex]
In point D:
For df = 70, the top 5% critical t score
tcrit = -1.666914479
[tex]\to -1.666914479 = \frac{(x - 81)}{8}\\\\\to -1.666914479 \times 8= (x - 81)\\\\\to -13.335315832= (x - 81)\\\\\to -13.335315832+81 = x \\\\\to x = 67.664684168\\\\[/tex]
In point E:
The lower cutoff is 0.10 in the center, which would be around 80 %. The critical point therefore is
tcrit = -1.293762898
[tex]\to -1.293762898 = \frac{(x-81)}{8}\\\\\to -1.293762898 \times 8= (x-81) \\\\\to -1.293762898 \times 8= (x-81) \\\\\to -10.350103184=x-81\\\\\to -10.350103184+81=x\\\\\to x=70.649896816[/tex]
In point F:
The lower cutoff is 0.90 in the center, which would be around 80 %. The critical point therefore is
tcrit = 1.293762898
[tex]\to 1.293762898 = \frac{(x-81)}{8}\\\\\to 1.293762898 \times 8= x-81\\\\\to 10.350103184 =x-81\\\\\to 10.350103184 +81=x\\\\\to x = 91.350103184\\[/tex]
Please please help please
Answer:
Greater Than [The second choice]
Step-by-step explanation:
What is the range of y=4sin(x)-2
Answer:
According to me it should be -6 [tex]\leq[/tex] y [tex]\leq[/tex] 2.
Step-by-step explanation:
This figure was broken into a triangle and a parallelogram as shown. Use the figures to complete the statements. The height of the triangle his in. The area of the triangle is vin.? The area of the parallelogram is in. 2 ? The area of the irregular figure is in. 2. ? h 22 in. 8 in. 10 in. Nin. 8 in. 8 in.
Answer: Use the figures to complete the statements.
The height of the triangle h is
✔ 12
in.
The area of the triangle is
✔ 48
in.2.
The area of the parallelogram is
✔ 80
in.2.
The area of the irregular figure is
✔ 128
in.2.
Step-by-step explanation: I js now got it right by the power of guessing
Simplify: 10(-5x+4)
Jejdjejehhe
Answer:
-50x + 40
Step-by-step explanation:
10(-5x+4)
-50x + 40
solve the system of linear equations by elimination. 6x-4y=18 3x+2y=-3
Answer:
y = -3
x = 1
Step-by-step explanation:
6x-4y=18
3x+2y=-3, so 3x = -2y - 3, then x = (-2y - 3)/3
substitute for x:
6((-2y - 3)/3) - 4y = 18
2(-2y - 3) - 4y = 18
-4y - 6 - 4y = 18
-8y - 6 = 18
-8y = 24
y = -3
x = (-2(-3) -3)/3 = 1
Solve: 2x-3 = 5(x + 6)
Answer:
2x - 3 = 5(x + 6)
2x - 3 = 5x + 30
-33 = 3x
x = -11
Answer:
x= -11
Step-by-step explanation:
1. Expand and distribute.
2x - 3 = 5x + 30
2. Subtract 2x from both sides.
2x - 3 = 5x + 30
-2x -2x
---------------------
-3 = 3x + 30
4 Subtract 30 from both sides.
-3 = 3x + 30
-30 -30
---------------------
-33 = 3x
6. Divide both sides by 33.
-33/3 = 3x/3
-11 = x
7. Switch sides
x = -11
HELP DUE IN 2 MINUTESS!!!! PLS HELP
An Urn contains 6 red marbles and 9 white marbles. A marble is drawn and put back into the urn. Both marbles were red. If another marble is drawn, what is the probability of it being white?
Answer:
3/5
Step-by-step explanation:
favorable outcomes/total number of outcomes=probability
Answer:
[tex] \frac{3}{5} [/tex]
Step-by-step explanation:
Previous extractions do not influence the probability