Complete Question
A few years ago, people tended to have relatively large CD collections. For students at a large university in the midwest, the mean number of CDs owned was 78 with a standard deviation of 90. To confirm these numbers, a random sample of 120 students from this university was collected and the size of their CD collections recorded. These particular 120 students had a mean CD collection size of 80 CDs. What is the numerical value of the sample mean?
Answer:
Sample Mean [tex]\=x=80[/tex]
Step-by-step explanation:
From the question we are told that:
Population Mean [tex]\mu=78[/tex]
Standard deviation [tex]\sigma=90[/tex]
Sample size [tex]n=120[/tex]
Sample Mean [tex]\=x=80[/tex]
Therefore
The numerical value of the sample mean is
Sample Mean [tex]\=x=80[/tex]
Help me with moth of these questions please
Answer:
10. CD + DE = CE
11. BC + CE = BE
Step-by-step explanation:
10. CD and DE lie on a straight line, therefore, CD + DE = CE based on the segment addition postulate.
11. BC and CE lie on a straight line, therefore, BC + CE = BE based on the segment addition postulate.
We have just performed a one-way ANOVA on a given set of data and rejected the null hypothesis for the ANOVA F test. Assume that we are able to perform a randomized block design ANOVA on the same data. For the randomized block design ANOVA, the null hypothesis for equal treatments will ________ be rejected.
Answer:
The answer is "sometimes".
Step-by-step explanation:
A one-way ANOVA was merely performed on one collected data and the null hypothesis was rejected after an ANOVA F test. Assume we could randomize ANOVA block design with the same information. This null hypothesis for full equality is sometimes rejected for the randomized complete block design ANOVA. Therefore we understand the use of randomized ANOVA block if the null hypothesis is denied of a one-way ANOVA but the rejection of a null RBD ANOVA hypothesis isn't conditional mostly on denial of the yet another ANOVA null.
Peter organizes morning hikes for his friends every Saturday. When the hiking trail is 3 km long, 19 friends join him and when the trail is 5 km long, only 7 friends tag along. There exists a linear relationship between the distance of the hiking trail (in km) and the number of friends who tag along. The number of friends depend on the distance of the trail. Determine how many friends will tag along to a hiking trail of 2 km.
Answer:
25
Step-by-step explanation:
x = distance of the hike
y = number of friends coming along
so, we are looking for a linear relationship between these two.
y = ax + b
we need to find the factor a and the constant offset b.
19 = a×3 + b
7 = a×5 + b
7 - b = a×5
a = (7-b)/5
19 = (7-b)×3/5 + b
19 = (21 - 3b)/5 + b
95 = 21 - 3b + 5b
74 = 2b
b = 37
a= (7-37)/5 = -30/5 = -6
so, the relationship is
y = -6x + 37
for 2km hiking
y = -6×2 + 37 = -12 + 37 = 25 friends
A die is rolled nine times and the number of times that two shows on the upper face is counted. If this experiment is repeated many times, find the mean for the number of twos.
Answer:
[tex]E(x) = 1.5\\[/tex]
Step-by-step explanation:
Given
[tex]n = 9[/tex] -- number of rolls
Required
The mean of 2's
The distribution follows binomial distribution where:
[tex]X \to Binomial(n,p)[/tex]
In this case:
[tex]p= \frac{1}{6}[/tex] ---- the theoretical probability of rolling 2
So, the mean of 2's is calculated using:
[tex]E(x) = np[/tex]
[tex]E(x) = 9 * \frac{1}{6}[/tex]
[tex]E(x) = \frac{9}{6}[/tex]
Simplify
[tex]E(x) = \frac{3}{2}[/tex] or
[tex]E(x) = 1.5\\[/tex]
Unit sales for new product ABC have varied in the first seven months of this year as follows: Month Jan Feb Mar Apr May Jun Jul Unit Sales 148 329 491 167 228 285 441 What is the (population) standard deviation of the data
Answer:
[tex]\sigma = 121.53[/tex]
Step-by-step explanation:
Required
The population standard deviation
First, calculate the population mean
[tex]\mu = \frac{\sum x}{n}[/tex]
This gives:
[tex]\mu = \frac{148+ 329+ 491 +167+ 228+285+ 441}{7}[/tex]
[tex]\mu = \frac{2089}{7}[/tex]
[tex]\mu = 298.43[/tex]
The population standard deviation is:
[tex]\sigma = \sqrt{\frac{\sum(x - \bar x)^2}{n}}[/tex]
So, we have:
[tex]\sigma = \sqrt{\frac{(148 - 298.43)^2 + ..........+ (441- 298.43)^2}{7}}[/tex]
[tex]\sigma = \sqrt{\frac{103387.7143}{7}}[/tex]
[tex]\sigma = \sqrt{14769.6734714}[/tex]
[tex]\sigma = 121.53[/tex]
The product of -3x and (2x+5) is …
[tex]\huge{\boxed{\boxed{ Solution ⎇}}} \ [/tex]
[tex] - 3x \times (2x + 5) \\ = - 3x \times 2x + - 3x \times 5 \\ = - 6x ^{2} - 15x[/tex]
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ ツ
꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐
[tex] \huge\boxed{\mathfrak{Answer}}[/tex]
[tex] - 3x \times (2x + 5) \\ = - 3x \times 2x + - 3x \times 5 \\ = - 6x ^{2} - 15x [/tex]
Answer ⟶ - 6x² - 15x
An environmentalist would like to estimate the true mean weight of all cars. To do so, she selects a random sample of
30 cars and determines that the 90% confidence interval for the true mean weight to be 2.8 to 3.4 tons. Which of the
following would increase the margin of error for this confidence interval?
O selecting another sample
O increasing the sample size
O increasing the confidence level
O decreasing the confidence level
If the confidence level will increase, the margin of error will also increases.
What is margin of error?The margin of error is defined a range of values below and above the sample statistic in a confidence interval.
What is confidence interval?The confidence interval is a way to show what is uncertainty is with a certain statistic.
According to the given question
Environmentalist estimating true mean weight or all cars.
For the true mean weights of 2.8 to 3.4 tons the confidence level is 90%.
Since, the confidence level increases, the critical value increases and hence the margin of error increases.
Therefore, if the confidence level will increase, the margin of error will also increases.
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The principle of redundancy is used when system reliability is improved through redundant or backup components. Assume that a student's alarm clock has a 15.3% daily failure rate. Complete parts (a) through (d) below. a. What is the probability that the student's alarm clock will not work on the morning of an important final exam?
Answer:
[tex]Pr = 0.153[/tex]
Step-by-step explanation:
Given
[tex]p = 15.3\%[/tex]
Required
Probability of alarm not working
[tex]p = 15.3\%[/tex] implies that the alarm has a probability of not working on a given day.
So, the probability that the alarm will not work on an exam date is:
[tex]Pr = 15.3\%[/tex]
Express as decimal
[tex]Pr = 0.153[/tex]
Anyone know this question?
Answer:
[tex](f + g)(4) = 191[/tex]
Step-by-step explanation:
Given
[tex]f(x) = 5x^2 - 5x + 15[/tex]
[tex]g(x) = 6x^2 + 7x - 8[/tex]
Required
[tex](f + g)(4)[/tex]
First, calculate [tex](f + g)(x)[/tex]
This is calculated as:
[tex](f + g)(x) = f(x) + g(x)[/tex]
So, we have:
[tex](f + g)(x) = 5x^2 - 5x + 15+6x^2 + 7x - 8[/tex]
Collect like terms
[tex](f + g)(x) = 5x^2 +6x^2 - 5x+ 7x + 15 - 8[/tex]
[tex](f + g)(x) = 11x^2 + 2x + 7[/tex]
Substitute 4 for x
[tex](f + g)(4) = 11*4^2 + 2*4 + 7[/tex]
[tex](f + g)(4) = 191[/tex]
Please explain the misleading
There are more compact cars (4*10 = 40) compared to trucks (2*10 = 20); however, the pictogram might make it appear that there are more trucks because the individual truck icon is larger compared to an individual compact car icon.
To anyone giving this image a quick glance, they may erroneously conclude that there are more trucks since their eye would notice the trucks first. Also, the person might think there are more trucks because bigger sizes tend to correspond to more proportion.
In real life, a truck is larger than a compact car, but the icons need to be the same size to have the figure not be misleading.
A very similar issue happens with the mid-size cars vs the compact cars as well. The three mid-size car icons span the same total width as the compact cars do, indicating that a reader might mistakenly conclude that there are the same number of mid-size cars compared to compact ones (when that's not true either).
2.7.2 : Checkup - Practice Problems
Find the perimeter of a football field which measures 90m by 60m
Hello!
[tex]\large\boxed{P = 300m}[/tex]
Use the following formula for the perimeter:
P = 2l + 2w, where:
l = length
w = width
Therefore:
P = 2(90) + 2(60)
Simplify:
P = 180 + 120 = 300 m
Answer:
well how about you use common sense 100 yards long on each side 200 yards then add 5o yards since the the that is how wide it is then add another 50 and you get 300 yards then convert that to meters
NEED ANSWER QUICK WITH STEP BY STEP!!!
A professor creates a histogram of test scores for 26 students in a statistics course. What is the probability of a student having scored between 65 and 100
Complete Question
Complete is Attached Below
Answer:
Option D
Step-by-step explanation:
From the question we are told that:
Sample size [tex]n=26[/tex]
Student scoring [tex]65-100 n'=12[/tex]
Generally the equation for probability of a student having score between 65 and 100 is mathematically given by
[tex]P(65-100)=\frac{12}{26}[/tex]
[tex]P(65-100)=12/26[/tex]
[tex]P(65-100)=0.462[/tex]
Option D
the perimeter of a rectangle parking lot is 322M if the width of the parking lot is 74M what is its length
Step-by-step explanation:
Perimeter of rectangle = 2( l+b)
Ie, P = 2( L+B )
In substituting,
322 = 2( L + 74)
Ie, 322 = 2L + 148
Re - arrange
Hence,
2L = 322 - 148
2L = 174
Thus, L = 174/2
L = 87M
The probability that an individual has 20-20 vision is 0.18. In a class of 12 students, what is the probability of finding five people with 20-20 vision?
0.417 or 0.185 or 0.18 or 0.037
Answer:
0.417
Step-by-step explanation:
Just divide 12/5 and the answer is 0.416666666...
Round up and you get 0.417.
Hope this helped!
I WILL MARK BRAINLIEST PLEASE HELP! This graph represents f(x), and g(x) = -7x + 8.
Which statement about these functions is true?
A.
Function f(x) is increasing, and g(x) is decreasing.
B.
Function f(x) is decreasing, and g(x) is increasing.
C.
Functions f(x) and g(x) are both decreasing.
D.
Functions f(x) and g(x) are both increasing.
Answer:
A
Step-by-step explanation:
ITS OPTION (A)
PLZ MARK ME BRAINLIEST..
Keith used the following steps to find the inverse of f, but he thinks he made an error.
Please explain absolute values?
Answer:
the magnitude of a real number without regard to its sign.
Step-by-step explanation:
For example, |-3| would just be a 3 in general, no negative sign in the front.
hope this answers your confusion.
In how many ways can a sample of 6 keyboards be selected so that exactly two have an electrical defect
Answer:
15ways
Step-by-step explanation:
This is a combination question since combination has to do with selection. Hence the number of ways sample of 6 keyboards can be selected so that exactly two have an electrical defect is expressed as;
6C2 = 6!/(6-2)!2!
6C2 = 6!/4!2!
6C2 = 6×5×4!/4!×2
6C2 = 6×5/2
6C2 = 30/2
6C2 = 15
Hence this can be done in 15ways
PLESE HELP WITH ANSWER. rewrite the function in the given form
s hard and too long I'm only of class 13
For this problem what I did was add all the measurements and I got 48 m. However, it is wrong. How do I go about solving the perimeter then?
9514 1404 393
Answer:
66 m
Step-by-step explanation:
The perimeter is the sum of the measures of all of the sides. There are two side measures that are missing from the diagram.
The missing horizontal measure is ...
17 m - 8 m = 9 m
The missing vertical measure is ...
16m -7 m = 9 m.
If you add these to the sum you already calculated, you will get the correct answer:
48 m + 9 m + 9 m = 66 m . . . perimeter of the figure
_____
If you're paying attention, you see that the sum of the measures of the two shorter horizontal segments is the same as the measure of the longer horizontal segment. Likewise, the sum of the measurements of the two shorter vertical segments is the same as that of the longer vertical segment.
In other words, the perimeter of this (and any) L-shaped figure is the same as the perimeter of a rectangle having the same horizontal and vertical dimensions as the long sides of the figure.
P = 2(17 m +16 m) = 2(33 m) = 66 m
According to the Venn Diagram below and given that P(A) = .4 as well as
P(B) = .3 what is P(AUB)?
Hello,
P(A)=0.4
P(B)=0.3
P(AUB)+P(A∩B)=P(A)+P(B)
P(AUB)=0.4+0.3-0.1=0.6
Answer C
The correct answer is option (C).
P(A ∪ B) = 0.6
Formula to find P(A ∪ B):If A, B are two different events then P(A U B) = P(A) + P(B) - P(A ∩ B)
We have been given, P(A) = 0.4, P(B) = 0.3
From given Venn diagram,
P(A ∩ B) = 0.10
Now, P(A U B) = P(A) + P(B) - P(A ∩ B)
⇒ P(A U B) = 0.4 + 0.3 - 0.10
⇒ P(A ∪ B) = 0.6
Therefore, the correct answer is option (C) .6
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Elise's math exam had 50 problems on it. She was able
to do 36 of them in 1 hour. What percent of the math problems did
she complete?
Answer:
72%
Step-by-step explanation:
Elise did 36 out of 50 problems in 1 hour. Another way to write 36 out of 50 is 36/50.
To find the percent from a fraction, one thing we can do is make the denominator 100 but still make the fraction the same, and then take the numerator.
We have 36/50, but want to make the denominator 100, not 50. We know that 100/50 = 2, so we have to multiply 50 by 2 to get 100.
Keeping the fraction equal, we can multiply 36/50 by 2/2 to get 72/100. We can do this because 2/2=1, so we are keeping the fraction the same -- just changing the numbers a little bit.
A fraction of form x/100 is equal to x%, so 72/100 = 72% as our answer
Please help with problem
9514 1404 393
Answer:
∠CAE ≈ 16.7°DF ≈ 5.3Step-by-step explanation:
a) Angle CAE can be found using the tangent relation.
tan(∠CAE) = CE/AE
tan(∠CAE) = 6/20
∠CAE = arctan(6/20) ≈ 16.7°
__
b. The length of DF can be found using the law of cosines.
DF² = FA² +DA² -2·FA·DA·cos(A)
DF² = 14² +10² -2·14·10·cos(16.7°) ≈ 27.8086
DF ≈ √27.8086
DF = 5.3
Round 36.319 to the nearest tenth
Jose bought a piece of fabric that was 5.6 meters long. From that, he cut 0.4
meter. How much fabric is left?
Answer:
Jose has 5.2 meters of fabric left.
Step-by-step explanation:
5.6 - 0.4 = 5.2
help with algebra pls help
9514 1404 393
Answer:
a. 1.48 seconds
Step-by-step explanation:
You want to find the larger value of t such that h(t) = 10.
-16t^2 +25t +8 = 10
16t^2 -25t +2 = 0 . . . . subtract the left side to get standard form
Using the quadratic formula, we find the values of t to be ...
t = (-(-25) ± √((-25)^2 -4(16)(2)))/(2(16)) = (25±√497)/32
t ≈ 0.08 or 1.48
The ball goes in the hoop about 1.48 seconds after it is thrown.
__
Additional comment
The quadratic formula tells us the solution to ...
ax² +bx +c = 0
is given by ...
[tex]x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
Here, we have a=16, b=-25, c=2. Of course, our variable is t, not x, but the relation is the same.
A system of equations is said to be redundant if one of the equations in the system is a linear combination of the other equations. Show by using the pivot operation that the following system is redundant. Is this system equivalent to a system of equations in canonical form?
a) x1 +x2 −3x3 = 7
b) −2x1 +x2 +5x3 = 2
c) 3x2 −x3 = 16
Answer:
prove that The given system of equations is redundant is attached below
Step-by-step explanation:
System of equations
x1 +x2 −3x3 = 7
−2x1 +x2 +5x3 = 2
3x2 −x3 = 16
To prove that the system is redundant we will apply the Gaussian elimination ( pivot operation )
attached below is the solution
the number of cases of a new diease can be modeled by the quadratic
Step-by-step explanation:
The number of cases of a new disease may be modeled by the quadratic regression equation y=-2x^2+44x+8 , what is the best prediction for the number of cases after 20 years ( the carrot symbol (^) means the following number is the exponent)
