Answer:
The weight of the dog is 12 pounds and the weight of the cat is 4 pounds.
Step-by-step explanation:
Let d represent the weight of the dog. Let c represent the weight of the cat.
Let's make a system of equations.
d+c=16
d=3c
We can use subsitution.
3c+c=16
4c=16
c=4
We can subsitute back into one of the two equations to find the weight of the dog.
d=3c
d=3(4)
d=12
The weight of the dog is 12 pounds and the weight of the cat is 4 pounds.
Two samples each of size 20 are taken from independent populations assumed to be normally distributed with equal variances. The first sample has a mean of 43.5 and standard deviation of 4.1 while the second sample has a mean of 40.1 and standard deviation of 3.2. A researcher would like to test if there is a difference between the population means at the 0.05 significance level. What can the researcher conclude?
Answer:
[tex]t=\frac{(43.5 -40.1)-(0)}{3.678\sqrt{\frac{1}{20}+\frac{1}{20}}}=2.923[/tex]
The degrees of freedom are
[tex]df=20+20-2=38[/tex]
And the p value is given by:
[tex]p_v =2*P(t_{38}>2.923) =0.0058[/tex]
Since the p value for this cae is lower than the significance level of 0.05 we have enough evidence to reject the null hypothesis and we can conclude that the true means for this case are significantly different
Step-by-step explanation:
When we have two independent samples from two normal distributions with equal variances we are assuming that
[tex]\sigma^2_1 =\sigma^2_2 =\sigma^2[/tex]
And the statistic is given by this formula:
[tex]t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2}}}[/tex]
Where t follows a t distribution with [tex]n_1+n_2 -2[/tex] degrees of freedom and the pooled variance [tex]S^2_p[/tex] is given by this formula:
[tex]S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}[/tex]
The system of hypothesis on this case are:
Null hypothesis: [tex]\mu_1 = \mu_2[/tex]
Alternative hypothesis: [tex]\mu_1 \neq \mu_2[/tex]
We have the following data given:
[tex]n_1 =20[/tex] represent the sample size for group 1
[tex]n_2 =20[/tex] represent the sample size for group 2
[tex]\bar X_1 =43.5[/tex] represent the sample mean for the group 1
[tex]\bar X_2 =40.1[/tex] represent the sample mean for the group 2
[tex]s_1=4.1[/tex] represent the sample standard deviation for group 1
[tex]s_2=3.2[/tex] represent the sample standard deviation for group 2
First we can begin finding the pooled variance:
[tex]\S^2_p =\frac{(20-1)(4.1)^2 +(20 -1)(3.2)^2}{20 +20 -2}=13.525[/tex]
And the deviation would be just the square root of the variance:
[tex]S_p=3.678[/tex]
The statistic is givne by:
[tex]t=\frac{(43.5 -40.1)-(0)}{3.678\sqrt{\frac{1}{20}+\frac{1}{20}}}=2.923[/tex]
The degrees of freedom are
[tex]df=20+20-2=38[/tex]
And the p value is given by:
[tex]p_v =2*P(t_{38}>2.923) =0.0058[/tex]
Since the p value for this cae is lower than the significance level of 0.05 we have enough evidence to reject the null hypothesis and we can conclude that the true means for this case are significantly different
Using the t-distribution, as we have the standard deviation for the sample, it is found that the researcher can conclude that there is a difference between the population means at the 0.05 significance level.
What are the hypothesis tested?At the null hypothesis, it is tested if there is no difference, that is:
[tex]H_0: \mu_1 - \mu_2 = 0[/tex]
At the alternative hypothesis, it is tested if there is a difference, that is:
[tex]H_a: \mu_1 - \mu_2 \neq 0[/tex]
What is the mean and the standard error of the distribution of differences?For each sample, we have that they are given by
[tex]\mu_1 = 43.5, s_1 = \frac{4.1}{\sqrt{20}} = 0.9168[/tex]
[tex]\mu_2 = 40.2, s_2 = \frac{3.2}{\sqrt{20}} = 0.7155[/tex]
Hence, for the distribution of differences, the mean and the standard error are given by:
[tex]\overline{x} = \mu_1 - \mu_2 = 43.5 - 40.2 = 3.3[/tex]
[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{0.9168^2 + 0.7155^2} = 1.163[/tex]
What is the test statistic?It is given by:
[tex]t = \frac{\overline{x} - \mu}{s}[/tex]
In which [tex]\mu = 0[/tex] is the value tested at the null hypothesis, hence:
[tex]t = \frac{\overline{x} - \mu}{s}[/tex]
[tex]t = \frac{3.3 - 0}{1.163}[/tex]
[tex]t = 2.84[/tex]
What is the decision?Considering a two-tailed test, as we are testing if the mean is different of a value, with a significance level of 0.05 and 20 + 20 - 2 = 38 df, the critical value is of [tex]|z^{\ast}| = 2.0244[/tex].
Since the absolute value of the test statistic is greater than the critical value, it is found that the researcher can conclude that there is a difference between the population means at the 0.05 significance level.
More can be learned about the t-distribution at https://brainly.com/question/16313918
PLZ HELP WILL RATE BRAINLIEST REMEMBER IT HAS 5 DIGITS
Answer:
The number: 13,226
Step-by-step explanation:
1. The smallest 5-digit number possibile is: 10,000
2. The smallest 5-digit number being odd should be: 10,001
3. All factors of 6 are {1, 2, 3, 6} so that the smallest possible way to arrange these numbers would be: 11,236
4. Now this number contains 3 prime numbers, 2 being {2 and 3}. If we were to consider another prime number, still being a factor of 6, that would be: 2. That would mean instead of the 1 being the second digit of the value 11,236 it could be 2: 12,236.
5. The digit in the thousands place (2) should be greater than the digit in the tens place (3). Let's swap these digits for now so that condition is satisfied: 13,226. 2 is the only number that has a number greater than it, besides 1, but 1 can't be a digit in the tenth place as it would make a greater 5 digit-number. Thus, provided the conditions are still satisfied, the number 13,226 is the smallest number possible.
A self storage center is a storage room that is 8 feet long, 6 feet wide, and 10 feet high. What is the volume of the room? 24 cubic feet 48 cubic feet 140 cubic feet 480 cubic feet
Answer:
Step-by-step explanation: answer is 480 cubic feet. Just do 8 x 6 x 10.
The body mass index (BMI) of an individual is a measure used to judge whether or not an individual is overweight. A BMI between 20 and 25 indicated a normal weight. In a survey of 750 men and 750 women, the Gallup organization found that 203 men and 270 women were normal weight. Construct a 95% confidence interval for the difference in proportion of men and women who are normal weight.
Given Information:
Number of Men having normal weight = 203
Number of Women having normal weight = 270
Sample size of Men = 750
Sample size of Women = 750
Confidence level = 95%
Required Information:
Difference in the proportion of normal weighted Men and Women = ?
Answer:
We are 95% confident that the difference in the proportion of Men and Women who are normal weight is between (0.044, 0.136)
Step-by-step explanation:
The proportion of Men who are normal weight is given by
p₁ = 203/750
p₁ = 0.27
The proportion of Women who are normal weight is given by
p₂ = 270/750
p₂ = 0.36
The difference in the proportion of normal weighted Men and Women is given by
[tex](p_2- p_1) \pm z\cdot \sqrt{\frac{p_1(1-p_1)}{n_1} + \frac{p_2(1-p_2)}{n_2}}[/tex]
Where p₁ and p₂ are the proportion of Men and Women who are normal weighted.
n₁ and n₂ are the sample size of Men and Women.
z is the value of z-score corresponding to 95% confidence level and is given by
[tex]z_{\alpha/2} = 1 - 0.95 = 0.05/2 = 0.025\\\\z_{0.025} = 1.96[/tex]
So we have z-score of 1.96 corresponding to confidence level of 95%
So the above equation becomes
[tex](p_2- p_1) \pm z\cdot \sqrt{\frac{p_1(1-p_1)}{n_1} + \frac{p_2(1-p_2)}{n_2}}\\\\(0.36- 0.27) \pm 1.96\cdot \sqrt{\frac{0.27(1-0.27)}{750} + \frac{0.36(1-0.36)}{750}}\\\\0.09\pm 1.96\cdot (0.0238) \\\\0.09\pm 0.046 \\\\Lower \: limit = 0.09 - 0.046 = 0.044\\\\Upper \: limit = 0.09 + 0.046 = 0.136\\\\(0.044, \: 0.136)[/tex]
Therefore, we are 95% confident that the difference in the proportion of Men and Women who are normal weight is between (0.044, 0.136)
How to find the value of z-score?
In the z-table find the probability of 0.025 and note down the value of that row it would be 1.9 and the value of column would be 0.06, therefore, the z-score is 1.9+0.06 = 1.96
256 divided by -16 with steps.
Answer:
256÷-16=16
Step-by-step explanation:
The complete expression is 256 divided by -16 is -16
How to determine the solution to the equationFrom the question, we have the following parameters that can be used in our computation:
256 divided by -16 = what
When represented as an equation, we have
Result = 256 divided by -16
Make the result the subject of the formula
So, we have
Result = 256/-16
Rewrite as
Result = -256/16
Evaluate the quotient
Result = -16
Hence, the number is -16
Read more about expressions at
https://brainly.com/question/30492964
#SPJ6
Let T: R^3 --> R^3 be a linear transformation. Let {v1, v2, v3} be a set of linearly dependent vectors in R^3. Show that the set {T(v1), T(v2), T(v3)} is also linearly dependent.
Answer:
Check the explanation
Step-by-step explanation:
Kindly check the attached image below to see the step by step explanation to the question above.
Need help with this math problem
Answer:
[tex]f(x)=-5x-3[/tex].
Step-by-step explanation:
From the given machine diagram it is clear that:
[tex]f(x)=-8[/tex] at [tex]x=1[/tex]
[tex]f(x)=-13[/tex] at [tex]x=2[/tex]
[tex]f(x)=-18[/tex] at [tex]x=3[/tex]
It is clear that the value of f(x) decreasing by 5 when the value of x is increasing by 1.
Since the function changing at a constant rate, therefore it represents a linear function.
If a linear function passing through two points, then the equation of line is
[tex]y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]
The given linear function passes through (1,-8) and (2,-13), therefore the linear equation is
[tex]y-(-8)=\dfrac{-13-(-8)}{2-1}(x-1)[/tex]
[tex]y+8=\dfrac{-5}{1}(x-1)[/tex]
[tex]y+8=-5(x-1)[/tex]
[tex]y=-5x+5-8[/tex]
[tex]y=-5x-3[/tex]
So, the required function is [tex]f(x)=-5x-3[/tex].
A camera crew on the ground is recording the act of a performer walking a tightrope stretched between two buildings. A member of the camera crew who is 1.8 m tall is almost directly below one end of the tightrope. When the performer steps out onto the other end of the tightrope, the angle of elevation is 75 . If the buildings are 30 m apart, how many meters above the ground is the performer?
Answer:
32332
Step-by-step explanation:
A music professor offers his 40 students the option of coming to an additional rehearsal session the week before their juries (musical final exams.) In order to decide whether these extra sessions actually help students, he keeps track of who attends them and compares their jury scores to those of students who did not schedule extra sessions. This study is a(n): A) matched pairs design. B) randomized block design. C) nonrandomized experiment. D) observational study. E) completely randomized experiment.
Answer:
D. Observational Study
Explanation:
An observational study is one in which all the participants are subjected to a common treatment and then compared to people who did not receive the same treatment. This is the case with the students who where subjected to the same treatment; an additional rehearsal session. They are then observed by the professor and compared to those who did not participate in the experiment.
This is also an example of a cohort observational study. A cohort observational study is one in which all the participants have a common uniting factor. They are made to undergo a treatment and then compared to those who did not receive the treatment. This type of study is subject to bias because a positive or negative result might be because of other factors not related to the study.
6
An ordinary fair dice is thrown once.
(a) On the probability scale mark with a cross (X) the probability ti
the dice lands on an even number.
1
2
(b) Write down the probability that the dice lands on a number les
than 3.
Answer:
(a) 1/2(b) 1/3Step-by-step explanation:
(a) 3 of the 6 numbers on the die are even, so the probability that one of them will show is 3/6 = 1/2.
__
(b) 2 of the 6 numbers on the die are less than 3, so the probability that one of them will show is 2/6 = 1/3.
What is the volume of this cube with a side length of 6 centimeters
6 cm
Answer:
V = 216 cm^3
Step-by-step explanation:
The volume of a cube is given by
V = s^3 where s is the side length
V = (6)^3
V = 216 cm^3
Answer:216 cm^3
Step-by-step explanation:
In cube, the length of all sides are equal
length of side=6cm
Volume of cube=length x length x length
Volume of cube=6 x 6 x 6
Volume of cube=216
Volume of cube=216 cm^3
Graph the circle (x-3)^2+(y-7)^2=4
a clock chimes once at 1, twice at 2
Answer:
3 times at 3
Step-by-step explanation:
A local retailer claims that the mean waiting time is less than 8 minutes. A random sample of 20 waiting times has a mean of 6.3 minutes with a standard deviation of 2.1 minutes. At α = 0.01, test the retailer's claim. Assume the distribution is normally distributed. Round the test statistic to the nearest thousandth.
Answer:
The claim is not true
Step-by-step explanation:
We are given that A local retailer claims that the mean waiting time is less than 8 minutes.
[tex]H_0:\mu=8[/tex]
[tex]H_a:\mu<8[/tex]
A random sample of 20 waiting times has a mean of 6.3 minutes with a standard deviation of 2.1 minutes.
[tex]\bar{x}=6.3[/tex]
s = 2.1
n = 20
Since n <30 and population standard deviation is unknown
So,we will use t test
So,[tex]t=\frac{x-\mu}{\frac{s}{\sqrt{n}}}[/tex]
[tex]t=\frac{6.3-8}{\frac{2.1}{\sqrt{20}}}[/tex]
t=-3.62
α = 0.01
Degree of freedom = df=n-1=20-1=19
[tex]t_{df,\frac{\alpha}{2}}=t_{19,\frac{0.01}{2}}=2.861[/tex]
t calculated < t critical
So, we failed to reject null hypothesis
Hence the claim is not true
Which value has an absolute deviation of 5 from the mean of this data set?
26, 12, 35, 28, 14
A 28
B. 35
C. 26
D. 14
Answer: 28
Step-by-step explanation: see prev. explanation
The absolute deviation of 5 from the mean of this data set is 28.
What is absolute deviation?
Absolute deviation is "the distance between each data point to the mean".
According to the question,
The data set is 26, 12, 35, 28, 14
Average of the data set = [tex]\frac{sum of the data value }{Total number of observation}[/tex]
= [tex]\frac{26+12+35+28+14}{5}[/tex]
= [tex]\frac{115}{5}[/tex]
= 23.
Thus, the average of the data set is 23.
In order to find absolute deviation of 5 subtract each data point from the mean.
26 - 23 = |3| = 3
12 - 23 = |-11| = 11
35 - 23 = |12| = 12
28 - 23 = |5| = 5
14 - 23 = |-9| = 9.
Hence, the absolute deviation of 5 is from the mean of the data set is 28.
Learn more about absolute deviation here
https://brainly.com/question/4364130
#SPJ2
Employees that work at a fish store must measure the level of nitrites in the water each day. Nitrite levels should remain lower than 5 ppm as to not harm the fish. The nitrite level varies according to a distribution that is approximately normal with a mean of 3 ppm. The probability that the nitrite level is less than 2 ppm is 0.0918.
1. Which of the following is closest to the probability that on a randomly selected day the nitrite level will be at least 5 ppm?
(A) 0.0039
(B) 0.0266
(C) 0.0918
(D) 0.7519
(E) 0.9961
Answer: .0039
Step-by-step explanation:
Classify this triangle.
Acute scalene triangle
Obtuse isosceles triangle
Right isosceles triangle
Right scalene triangle
Answer: right isosceles
Step-by-step explanation:
the angle at the bottom is right therefore you need to figure out the lengths of the sides to conclude if it is isosceles or scalene. because two of the sides are the same length and the other is not it is isosceles
3(12−5)+(8x8)-45? Answer?
Answer:
its 40
Step-by-step explanation:
i think
i don't really understand this yet, could someone please help?
Answer:
maybe show me a picture of what u want me to help u with and then Ill answer it
Which statement is true?
Parallelograms are trapezoids.
A square is always a rhombus.
A rhombus is always a square.
A rectangle is a trapezoid.
Answer:
A square is always a rhombus.
Explanation:
A square has 4 sides of equal length.
Answer:
A square is always a rhombusStep-by-step explanation: trapezoids have 3 angles and 3 sides so in that case rectangles and parallelograms are not trapezoids.rhombuses aren't always squares.Find two numbers for which the sum is 101 and the difference is 47
Answer:
74 and 27
Step-by-step explanation:
let x and y be the numbers
x + y =101........eqn 1
x - y = 47.......eqn 2
solve simultaneously
from equation 2, make x the subject
x= 47 + y........eqn 3
put eqn 3 into eqn 1
(47+y) + y = 101
47 + 2y = 101
2y= 101 - 47
2y=54
y= 54/2
y= 27
put y=27 into eqn 3
x = 47 + 27
x = 74
What is the area of the triangle?
PLSSS help me
Answer:
The area of the triangle is [tex]A=6 \:units^2[/tex].
Step-by-step explanation:
The area A of a triangle is given by the formula [tex]A=\frac{1}{2} bh[/tex] where b is the base and h is the height of the triangle.
From the graph, we can see that the base is 3 units and the height is 4 units. Therefore, the area of the triangle is
[tex]A=\frac{1}{2} \cdot3\cdot 4=\frac{12}{2}=6 \:units^2[/tex]
The cost, in dollars, to produce 1 watt of solar energy is a function of the number of years
since 1977.t.
From 1977 to 1987, the cost could be modeled by an exponential function. Here is the
graph of the function.
80
60
dollars per Watt
40
20
4
8
10
6
years since 1977
1. What is the statement f (9) 36 saying about this situation?
2. What is f(4)? What about f (3.5)? What do these values represent in this context?
3. When f(t) = 45, what is t? What does that value of t represent in this context?
4. By what factor did the cost of solar cells change each year? (If you get stuck consider
creating a table.)
Answer:
In the figure attached, the graph of the function is shown.
1. f(9) ≈ 6 means that at t = 9 (year 1977 + 9 = 1986) the cost to produce 1 watt of solar energy was $6
2. f(4) ≈ 25, which means at year 1981 (=1977 + 4) the cost was $25 per watt
f(3.5) ≈ 28, which means at half of year 1980 (=1977 + 3.5) the cost was $28 per watt
3. When f(t) = 45, t is equal to 2, which means that the year wass 1979 (= 1977 + 2)
4. From the graph we can compute the following table:
x | y
0 | 80
1 | 60
The general exponential decay formula is:
f(x) = a*b^x
where a is the initial value and b si the decay factor. Replacing with data from the table:
f(0) = a*b^0
80 = a
f(1) = a*b^1
60/80 = b
0.75 = b
"Only one remains." Ryan signals to his brother from his hiding place.
Matt nods in acknowledgement, spotting the last evil robot.
"34 degrees." Matt signals back, informing Ryan of the angle he observed between Ryan and the robot.
Col
Ryan records this value on his diagram (shown below) and performs a calculation. Calibrating his laser cannon to
the correct distance, he stands, aims, and fires.
To what distance did Ryan calibrate his laser cannon?
Do not round during your calculations. Round your final answer to the nearest meter.
Pro
m
Pro
Ryan
Tea
146 m
120°
Matt
34
Answer:
186m
Step-by-step explanation:
Brittany Monroe is a legal secretary. Her biweekly salary is $1,650.00 what is her annual salary?
Answer:
$42,900 a year
Step-by-step explanation:
so there are 26 bi-weeks in a year. (fun fact)
you take $1,650 and multiply that biweekly to get her annual salary.
1650*26=42,900
Find the mode of the following numbers.
21, 7, 19, 21, 60, 21, 19
Answer:
The mode is 21.
Step-by-step explanation:
Mode is a number than appears most frequently in a set of numbers.
Answer:
[tex]21[/tex]
Step-by-step explanation:
The Most frequently number that appears in a set of numbers is called as mode.
21 , 7 , 19 , 21 , 60 , 21 , 19
Now here we can clearly see that 21 is the most frequent number that appears in the text.
hope this helps
brainliest appreciated
good luck! have a nice day!
Determine if the set of vectors shown to the right is a basis for IR3 If the set of vectors is not a basis, determine whether it is linearly independent and whether the set 311-4 spans R 12 Which of the following describe the set?
A. The set is a basis for R3
B. The set is linearly independent.
C The set spans R3
D. None of the above
Answer:
The problem is clearly solved in the attachment
Which fraction is in simplest form 4/20 6/9 5/13 14/21
Answer: 5/13
Step-by-step explanation:
Answer:
5/13 is in simplest form, because it cannot be reduced any further.
Step-by-step explanation: 4/20 can be reduced to 1/5, 6/9 to 1/3, and 14/21 can be reduced to 2/3
A fraction that is equivalent to 6/-5?
Answer:
12/-10
Step-by-step explanation:
Any multiple of a fraction is the equivalent of the original fraction, the only difference is that it wont be fully simplified. If we multiply the original fraction (6/-5) by 2, both the numerator and denominator, you will get 12/-10.
Answer:
12/-10
Step-by-step explanation:
6/-5
6×2= 12
-5×2=-10
12/-10
Apply the distributive property to factor out the greatest common factor of all three terms. Explanation: 9-12x+6y what is the answer??
Answer: [tex]3(3-4x+2y)[/tex]
Step-by-step explanation:
[tex]9-12x+6y[/tex]
[tex]3(3-4x+2y)[/tex]