A student records the repair cost for 22 randomly selected dryers. A sample mean of $98.78 and standard deviation of $15.49 are subsequently computed. Determine the 95% confidence interval for the mean repair cost for the dryers. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Answer:
The critical value that should be used is T = 2.0796.
The 95% confidence interval for the mean repair cost for the dryers is between $91.912 and $105.648.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 22 - 1 = 21
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 21 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.0796, which is the critical value that should be used.
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.0796\frac{15.49}{\sqrt{22}} = 6.868[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 98.78 - 6.868 = $91.912
The upper end of the interval is the sample mean added to M. So it is 98.78 + 6.868 = $105.648
The 95% confidence interval for the mean repair cost for the dryers is between $91.912 and $105.648.
Two less than five times a number is equal to 10 more than seven times the number. What is the number?
Answer:
x = -6; the number is -6!
Step-by-step explanation:
This is a somewhat wordy question, but it is actually easy to solve once you write it down!
It should look like this:
[tex]5x-2=7x+10[/tex]
See? It's simple! Now we just solve from there.
[tex]5x-2=7x+10\\-2x-2=10\\-2x=12\\x=-6[/tex]
Have a nice day fam! Spread the love <3
I need help in this algebra problem plz
Answer:
X+2
Step-by-step explanation:
Solve for x.
7x - = 6x -
O x = 1/4
Ox=1
Ox= -1
O x = -1/4
Will give brainly
Answer:
D. - 1/4
Step-by-step explanation:
Answer:
-1/4
Step-by-step explanation:
0.375=3/8 0.625=5/8
7x-0.375=6x-0.625
1x=-0.25
-0.25=-1/4
Giving brainliest!!!!!
Answer:
434 [tex]cm^3[/tex]
Step-by-step explanation:
volume of bottom: 6 x 10 x 5 = 300 [tex]cm^3[/tex]
volume of top:
[tex]V = (\frac{4}{3}\pi r^3)/2\\\\= (\frac{4}{3}\pi(4)^3)/2\\[/tex]
≈ 134.041 [tex]cm^3[/tex]
300 + 134.041 = 434.041
they want to the nearest tenth, so it would just be 434.0
PLS ANSWER FAST WILL GIVE BRANLIEST
Answer:
m<RTS=63
m<PTQ=27
Step-by-step explanation:
8x-17=5x+13
x=10
5(10)+13=63
8(10)-17=63
<RTQ=<UTQ
90-63=27
Enter the measure of YVZ in degrees
Answer:
(3x+5)+(2x) = 90
5x + 5 = 90
5x = 85
x = 17
YVZ = 3×17 +5
=56°
A sample of 1300 computer chips revealed that 50% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature states that 47% of the chips do not fail in the first 1000 hours of their use. The quality control manager wants to test the claim that the actual percentage that do not fail is different from the stated percentage. Make the decision to reject or fail to reject the null hypothesis at the 0.01 level.
Answer:
The pvalue of the test is 0.03 > 0.01, which means that we fail to reject the null hypothesis at the 0.01 level.
Step-by-step explanation:
The company's promotional literature states that 47% of the chips do not fail in the first 1000 hours of their use. The quality control manager wants to test the claim that the actual percentage that do not fail is different from the stated percentage.
This means that at the null hypothesis we test that the proportion is 47% = 0.47, that is:
[tex]H_0: p = 0.47[/tex]
And at the alternate hypothesis, we test that the proportion is different from 47%, that is:
[tex]H_a: p \neq 0.47[/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.
47% is tested at the null hypothesis:
This means that [tex]\mu = 0.47, \sigma = \sqrt{0.47*0.53}[/tex]
A sample of 1300 computer chips revealed that 50% of the chips do not fail in the first 1000 hours of their use.
This means that [tex]n = 1300, X = 0.5[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{0.5 - 0.47}{\frac{\sqrt{0.47*0.53}}{\sqrt{1300}}}[/tex]
[tex]z = 2.17[/tex]
Pvalue of the test and decision:
The pvalue of the test is the probability that the proportion differs from 0.47 by at least 0.5 - 0.47 = 0.03, which is P(|Z| > 2.17), which is 2 multiplied by the pvalue of Z = -2.17
Z = -2.17 has a pvalue of 0.015
2*0.015 = 0.03
The pvalue of the test is 0.03 > 0.01, which means that we fail to reject the null hypothesis at the 0.01 level.
Question 7 (5 points)
Find the distance between a point (-3, 4) and a vertical line at x = 4.
A) -7
B) 8
O
C) 1
OD 7
Answer:
D.7
Step-by-step explanation:
[tex] 4 - ( - 3) = 4 + 3(because \: - \times - ) \: it \: is \: positive \\ = 7[/tex]
Evaluate the expression: -(8 - 12) + 6° + (-4)2.
Answer:
-4 + 6°
Step-by-step explanation:
- (8 - 12) + 6° + (- 4)2 = - ( - 4) + 6° - 8 = 4 + 6° - 8 = - 4 + 6°
find the value of x and is it congruent or not
Answer:
x would be 10.
It is congruent since two sides are given to be congruent. This can be proven with the SSS Congruence Postulate.
Anyone know wat 792 divided by 5 is?
Answer:
158.4 i think
Step-by-step explanation:
What's another name for qualitative variables?
Answer:
A qualitative variable, also called a categorical variable, is a variable that isn't numerical.
Find the sum of the following arithmetic series:
(a) 6-5-16 - .... -115 (b) 21
(c) 13 + 6 -1 - .... -106
Find the sum of the first 500 odd numbers.
Answer:
12345678910
Step-by-step explanation:
CHARRRRRRRRR joke lang bestie
a picture frame is 4 inches taller than it is wide and has an area of 192 square inches. What are the dimensions of the picture frame? using the quadratic method
thank you :)
Answer: width is 12, length is 16
Step-by-step explanation:
A= l*w
l=w+4
A=w(w+4)
[tex]A=192\\192=w^{2} +4w\\0=w^{2} +4w-192[/tex]
factor
(w+16)(w-12)
w= -16 or w=12
width is 12, length is 16
please help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
√11 = 3.31....
option 1. Irrational: √11 = 3.3
Answer:
Irrational [tex]\sqrt{11}[/tex] = 3.3
Step-by-step explanation:
Have a nice day!! :)
will someone help me with this?
height of movable brigde 37cm
width of movable brigde 85 cm
what is the domain of the function given below f(x)= log(x+5)-2
Answer:
Domain:
(
5
,
∞
)
,
{
x
|
x
>
5
}
Range:
(
−
∞
,
∞
)
,
{
y
|
y
∈
R
}
Step-by-step explanation:
Someone please help me answer this!1
Answer:
16 km is the answer
Step-by-step explanation:
a (Colton to parents' house) = 12 km
b = ?
c (parents' house to grandparents' house) = 20 km
According to the Pythagoras theorem,
a² + b² = c²
12² + b² = 20²
144 + b² = 400
b² = 400 - 144
b² = 256
b = 16
∴ Colton is 16 km away from his grandparents' house.
3 cm
.
.
5 cm
If the base is halved and the height is quadrupled, then which of the following statements
about its area will be true?
Answer:
I think 7
Step-by-step explanation:
if the moon is purple then what toothpaste do u use on your but
The quadrilateral shown is a rectangle. What is m∠ZVY?
A) 39°
B) 59°
C) 61°
D) 119°
Answer: hey bro i can solve this for you but you need to show the quadrilateral. without it i can't solve it.
Step-by-step explanation:
A parasail is at a height of 441 feet (or 0.083 miles) above sea level. The earth's radius is 3959 miles find the distance to the horizon to the parasail.
If you answer this can you please explain how to do it? I'm confused and just want to learn, but I don't understand how to solve it!
Answer:
The distance to horizon is 25.64 miles for the parasail.
Step-by-step explanation:
The distance to horizon for a given height is given as
[tex]d=\sqrt{2hR}[/tex]
Here
d is the distance to horizonh is the height of the observer which is given here as 0.083 milesR is the radius of Earth which is given as 3959 milesSo the distance becomes
[tex]d=\sqrt{2hR}\\d=\sqrt{2\times 0.083\times 3959}\\d=\sqrt{657.194}\\d=25.6357 \text{ miles}\\d=25.64\text{ miles}[/tex]
So the distance to horizon is 25.64 miles for the parasail.
the y coordinate is 7 more than the x coordinate
Answer:
if you have the value of x then y =x +7
PLZ HURRY
The two triangles below are similar. What is the ratio of the corresponding sde lengths? A. 4:9 B. 4:2 C. 26:26 D. 4.5:2
Answer:
Step-by-step explanation:
It is 4:9 and 4.5:2
Steve manages a skate park and he has been analyzing the attendance data. Steve finds that the number of visitors increases exponentially as the temperature increases, and this situation is represented by the function f(x) = 5x. Steve also finds a linear equation that models the number of people who leave the park early depending on the change in temperature, and it is represented by g(x) = −x + 6. The graph of the two functions is below. Find the solution to the two functions and explain what the solution represents.
Answer:
(1, 5)Step-by-step explanation:
Both of the graphs include infinite number of points.
The solution is the common point that belongs to both of the graphs, their intersection, which is the point (1, 5)
This is the point when the temperature change is positive 1 degree. At this point number of visitors is equal to number of those leaving the part early (5 visitors).
Answer:
(1,5)
Step-by-step explanation:
The graphs intersect at (1,5). At this point, the temperature change is 1 degree and the number of visitors is equal to those leaving early, which is 5 visitors.
find the size of each sample needed to estimate the difference between the proportions of boys and girls under 10 years old who are afraid of spiders. Assume that we want a 95% confidence level and that the error is smaller than 0.03.
Answer:
sample
Step-by-step explanation:
PLS ANSWER QUICK! Thanks!
Answer:
The correct answer would be [tex]a=\sqrt{c^2-b^2}[/tex]
Step-by-step explanation:
given [tex]a^2+b^2=c^2[/tex] we want to solve for a
How?
We can do this by using basic algebra ( isolating the variable (a ))
Step 1 subtract [tex]b^2[/tex] from each side
[tex]a^2+b^2-b^2=a^2\\c^2-b^2=c^2-b^2[/tex]
now we have [tex]a^2=c^2-b^2[/tex]
step 2 take the square root of each side
[tex]\sqrt{a^2} =a\\\sqrt{c^2-b^2} =\sqrt{c^2-b^2}[/tex]
we're left with [tex]a=\sqrt{c^2-b^2}[/tex]
Hence your answer is A
8x^2+1/9
the expression represents a....
quartic
cubic
quartic
linear
quadratic
Answer:
A. Quartic
Step-by-step explanation:
I went to desmos graphing,
8x^2+1/9 (plug it in and looked at the line)
It shows a parabola,
y-intercept: (0,0.111)
"Cubic functions. Three points not in a line determine a parabola, a polynomial function of degree 2. Polynomials of degree 2 are quadratic functions. Their graphs are parabolas."
Therefore, this is a quadratic ( quartic) since the degree in this parabola is 2.
What is the value of x and y?
Answer:
Step-by-step explanation:
[tex]\frac{x}{42}=tan 30=\frac{1}{\sqrt{3} }\\x=\frac{42}{\sqrt{3} } \times \frac{\sqrt{3}}{\sqrt{3}} =14\sqrt{3} \\\frac{42}{y} =\cos ~30=\frac{\sqrt{3}}{2} \\y=\frac{84}{\sqrt{3}} \times \frac{\sqrt{3}}{\sqrt{3}} =\frac{84 \sqrt{3}}{3} =28 {\sqrt{3}}[/tex]
(NO LINKS) A space shuttle travels at 2.6 x 10,000 feet per second. An hour is 3.6 x 1,000 seconds. This expression can be used to find the number of feet the space shuttle travels in an hour. How many feet does the shuttle travel in an hour?
Answer:
1) 7.22 ft in a hr & 2) Choice C. y = 0.50x + 2
Step-by-step explanation:
1) Space shuttle
2.6 x 10,000 = 26,000ft
3.6 x 1,000 = 3,600 seconds = 1 hr
26,000/3,600 = 7.22 ft in a hr
2) Taxi company
y = 0.50x + 2