Answer:
False
Step-by-step explanation:
We also need to show that it is true for n=1
and for n=k+1
A researcher is interested in finding a 90% confidence interval for the mean number of times per
day that college students text. The study included 147 students who averaged 44.7 texts per
day. The standard deviation was 17.9 texts. Round answers to 3 decimal places where possible.
a. To compute the confidence interval use a tv distribution.
b. With 90% confidence the population mean number of texts per day is between
and
texts.
Answer:
90% confidence the Population mean number of texts per day
(42.2561 ,47.1439)
Step-by-step explanation:
Step(i):-
Given sample size 'n' = 147
mean of the sample size x⁻ = 44.7
standard deviation of the sample 'S' = 17.9
90% confidence the Population mean number of texts per day
[tex](x^{-} - t_{\alpha } \frac{S}{\sqrt{n} } ,(x^{-} + t_{\alpha } \frac{S}{\sqrt{n} })[/tex]
Step(ii):-
Degrees of freedom
ν=n-1=147-1=146
t₀.₁₀ = 1.6554
[tex](x^{-} - t_{\alpha } \frac{S}{\sqrt{n} } ,(x^{-} + t_{\alpha } \frac{S}{\sqrt{n} })[/tex]
[tex](44.7 - 1.6554 \frac{17.9}{\sqrt{147} } ,(44.7 + 1.6554 \frac{17.9}{\sqrt{147} })[/tex]
(44.7 - 2.4439 ,44.7 + 2.4439 )
(42.2561 ,47.1439)
Conclusion:-
90% confidence the Population mean number of texts per day
(42.2561 ,47.1439)
WHY CAN'T ANYONE HELP ME PLEASE?A 40% solution of fertilizer is to be mixed with a 80% solution of fertilizer in order to get 80 gallons of a 70% solution. How many gallons of the 40% solution and 80% solution should be mixed? 40% solution =? gallons, 80% solution =? gallons
Answer:
40% solution = 20 gallons
80% solution = 60 gallons
Step-by-step explanation:
x = gallons of 40% solution
y = gallons of 80% solution
Total volume is:
x + y = 80
Total amount of fertilizer is:
0.40 x + 0.80 y = 0.70 (80)
Solve by substitution.
0.40 x + 0.80 (80 − x) = 0.70 (80)
0.40 x + 64 − 0.80 x = 56
0.40 x = 8
x = 20
y = 60
Factor 13ab3 + 39a2b5.
[tex]13ab^3+39a^2b^5\\\\\boxed{\boxed{\boxed{13ab^3(1+3ab^2)}}}\\\\[/tex]
Brazil number one.
Answer:
there's no answer for that equation
Time-series data are often graphically depicted how?
A. Bar chart.
B. Histogram.
C. Line chart.
D. All of these choices are true.
Answer:
C. Line chart
Step-by-step explanation:
Answer:
B. Histogram
Step-by-step explanation:
Histogram uses time.
The weights of a sample of college textbooks has a bell-shaped distribution with a mean of 8.1 p o u n d s ( l b s ) and a standard deviation of 2.1 l b s . According to the Empirical Rule, what percent of all college textbooks will weigh between 1.8 and 14.4 l b s ?
Answer:
The interval ( 1,8 ; 14,4 ) will contains 99,7 % of all values
Step-by-step explanation:
For Normal Distribution N ( μ ; σ ) the Empirical Rule establishes that in the intervals:
( μ ± σ ) we find 68,3 % of all values
( μ ± 2σ ) we find 95,4 % of all values
( μ ± 3σ ) we find 99,7 % of all values
Then we have a normal distribution N ( 8,1 ; 2,1 )
3*σ = 3* 2,1 = 6,3
And 8,1 - 6,3 = 1,8 8,1 + 6,3 = 14,4
Then the interval ( 1,8 ; 14,4 ) will contains 99,7 % of all values
In a survey of 200 publicly-traded companies, the average price-earnings ratio was 18.5 with a standard deviation of 8.2. When testing the hypothesis (at the 5% level of significance) that the average price-earnings ratio has increased from the past value of 16.8, the null and alternative hypotheses would be:________
Answer:
Null Hypothesis: H0:μ ≤ 16.8
Alternative Hypothesis: Ha: μ > 16.8
Step-by-step explanation:
We are told that affer testing the hypothesis (at the 5% level of significance), that the average price-earnings ratio increased from the past value of 16.8.
It means that the past value was not more than 16.8.
This follows that the null hypothesis is given as;
H0:μ ≤ 16.8
And since it has been discovered that the ratio increased from the past value of 16.8, the alternative hypothesis is;
Ha: μ > 16.8
Students who score within 14 points of the number 88 will pass a particular test. Write this statement using absolute value notation and use the variable x for the score.
Answer:
|88-x| ≤ 14
Step-by-step explanation:
their score has to be within 14 points of 88.
if their score is above 88, the number will be negative, but the absolute value makes the number positive. if that number is still within 14 of 88, they pass.
if their score is below 88, the number will be negative, and the absolute value keeps the number positive. if that number is still within 14 of 88, they pass.
ASAP Which condition does not prove that two triangles are congruent? A. ASA ≅ ASA B. SAS ≅ SAS C. SSA ≅ SSA D. SSS ≅ SSS
Answer:
The answer is C. SSA ≅ SSA.
Step-by-step explanation:
To check for similar triangles, SSA congruence would not work because the other side can be any length. Also, there is not an SSA postulate because this theorem by itself cannot prove congruence.
The other three properties do work because they show congruence unlike the other congruent factors.
Driver's Delight is considering building a new track. They have a circular space
with a diameter of 150 feet. Compute the circumference of the circular space.
Use 3.14 for it. Round your answer to the nearest hundredth, if necessary.
Answer:
The answer is 471 feetStep-by-step explanation:
Since the the track is circular
Circumference of a circle = πd
where
d is the diameter
π = 3.14
From the question
diameter = 150 feet
Circumference = 150π
= 150(3.14)
We have the final answer as
Circumference = 471 feetHope this helps you
Answer:
471.23 ft
Step-by-step explanation:
The circumference of this space is C = πd = (150 ft)π, or approximately
471.23 ft
Can someone help me, please?
Answer:
16
Step-by-step explanation:
7x+20+2x-5=159
9x+15=159
9x=159-15
9x=144
x=16
:( I Need help! Show work please! Aviva has a total of 52 coins, all of which are either dimes or nickels. The total value of the coins is $4.70. Find the number of each type of coin.
Answer:
42 Dimes, 10 Nickels.
Step-by-step explanation:
Dimes are worth $0.10, nickels are worth $0.05.
If D = number of dimes, and N = number of nickels, then the following equations are true:
0.10D + 0.05N = 4.70
D + N = 52
Next, let's multiply the first equation by 10 so that we can subtract the second one from it.
D + 0.50N = 47
(-) D + N = 52
Subtracting the second equation from the first one gives:
-0.5N = -5
-0.5N/-0.5 = -5/-0.5
N = 10
Finally, substitute N in the original second equation to find D.
D + 10 = 52
D + 10 - 10 = 52 - 10
D = 42
8÷2(2+2)=?
I asked a few people some say it’s 1 and some say 16....
Answer:
16
Step-by-step explanation:
Follow the rules of PEMDAS
8÷2(2+2)
Parentheses
8÷2(4)
Exponents
we have none
Multiply and Divide from left to right
4(4)
16
Then Add and Subtract from left to right
Answer:
16
Step-by-step explanation:
In order to understand the answer to the problem, we need to know the correct order of operations, through the acronym PEMDAS
PEMDAS
P: Parentheses
E: Exponent
M: Multiply
D: Divide
A: Add
S: Subtract
First add everything in the parentheses to get 4
Then divide 8 by 2 to get 4
4 times 4 = 16
8/2= 4
2+2=4
4 x 4 = 16
Find the probability.
Two dice are rolled. Find the probability that the score on the dice is either 5 or
10.
Answer:
7/36
Step-by-step explanation:
1 die has 6 faces
When two dice are rolled, the total number of outcomes
= 6 × 6 = 36
The Probability of having(5) =
(1 & 4), (2 & 3) , ( 3 & 2), (4 & 1)
= 4
The probability of having (10) =
(5 & 5), (4 & 6) , ( 6 & 4)
= 3
The probability that the score on the dice is either 5 or 10.
P(5) + P(10)
= 4/36 + 3/36
= 7/36
Answer: 7/36
Step-by-step explanation:
36 outcomes
4 chances of getting 5 (1+4, 2+3, 4+1, 3+2)
3 chances of getting 10 (4+6, 5+5, 6+4)
4+3=7
so 7/36 chance
Find the sum of the infinite geometric series -27, -9, -3, … The ratio is /3 and u1 is -27
===================================================
Work Shown:
a = -27 = first term
r = 1/3 = common ratio, note how this is between -1 and 1
We start with -27 and multiply by 1/3 each time to get the next term
S = infinite sum
S = a/(1-r), which only works because -1 < r < 1 is true
S = -27/(1-1/3)
S = -27/(2/3)
S = (-27/1) divided by (2/3)
S = (-27/1) times (3/2)
S = (-27*3)/(1*2)
S = -81/2
As you generate and add up the terms of the sequence, the infinite sum slowly starts to approach -81/2 = -40.5; we'll never actually achieve this sum exactly. Think of it as approaching an asymptote.
if it can be assumed that the population is normal, then what is the probability that one man sampled from this population has a weight between 72kg and 88kg
Answer:
The probability that one man sampled from this population has a weight between 72kg and 88kg is 0.6826.
Step-by-step explanation:
The complete question has the data of mean = 80 kg and standard deviation = 8kg
We have to find the probability between 72 kg and 88 kg
Since it is a normal distribution
(x`- u1 / σ/ √n) < Z >( x`- u2 / σ/ √n)
P (72 <x>88) = P ( 72-80/8/√1) <Z > ( 88-80/8/√1)
= P (-1<Z> 1) = 1- P (Z<1) - P (Z<-1)
= 1- 0.8413- (- 0.8413)= 1- 1.6826= 0.6826
So the probability that one man sampled from this population has a weight between 72kg and 88kg is 0.6826.
75% of this
number is 13.5
Answer:
10.125
Step-by-step explanation:
Hello!
To find this we first have to convert the percentage to a decimal
We do this by moving the decimal point two times left
75.0% = 0.75
Now we multiply this by the number
13.5 * 0.75 = 10.125
The answer is 10.125
Hope this helps!
Use the information provided to determine a 95% confidence interval for the population variance. A researcher was interested in the variability in service time (in hours) spent by mechanics fixing the same automotive problem. A random sample was taken resulting in a sample of size 20 from a substantial file of reported experience. The summary statistics are as follows: n = 20, sample mean = 13.8 hours, sample standard deviation = 3.9 hours. Assume service time follows a normal distribution. Round to two decimal places.
Answer:
The 95% confidence interval for the population variance is (8.80, 32.45).
Step-by-step explanation:
The (1 - α)% confidence interval for the population variance is given as follows:
[tex]\frac{(n-1)\cdot s^{2}}{\chi^{2}_{\alpha/2}}\leq \sigma^{2}\leq \frac{(n-1)\cdot s^{2}}{\chi^{2}_{1-\alpha/2}}[/tex]
It is provided that:
n = 20
s = 3.9
Confidence level = 95%
⇒ α = 0.05
Compute the critical values of Chi-square:
[tex]\chi^{2}_{\alpha/2, (n-1)}=\chi^{2}_{0.05/2, (20-1)}=\chi^{2}_{0.025,19}=32.852\\\\\chi^{2}_{1-\alpha/2, (n-1)}=\chi^{2}_{1-0.05/2, (20-1)}=\chi^{2}_{0.975,19}=8.907[/tex]
*Use a Chi-square table.
Compute the 95% confidence interval for the population variance as follows:
[tex]\frac{(n-1)\cdot s^{2}}{\chi^{2}_{\alpha/2}}\leq \sigma^{2}\leq \frac{(n-1)\cdot s^{2}}{\chi^{2}_{1-\alpha/2}}[/tex]
[tex]\frac{(20-1)\cdot (3.9)^{2}}{32.852}\leq \sigma^{2}\leq \frac{(20-1)\cdot (3.9)^{2}}{8.907}\\\\8.7967\leq \sigma^{2}\leq 32.4453\\\\8.80\leq \sigma^{2}\leq 32.45[/tex]
Thus, the 95% confidence interval for the population variance is (8.80, 32.45).
group the like term together
Answer:
Step-by-step explanation:
[tex]xy^{2}[/tex], [tex]5y^{2}x[/tex], [tex]\frac{-3}{5}[/tex][tex]xy^{2}[/tex]
[tex]-3x^{2}y[/tex], [tex]\frac{2}{3}[/tex][tex]yx^{2}[/tex]
Hope this helps
plz mark it as brainliest!!!!!
Chris wanted to know how likely he is to win at his favorite carnival game. He conducted 50 tests and won 15 times. What is the probability that he will win next time he plays? All answers are rounded to the nearest hundredth. a.) 0.15 b.) 0.30 c.) 0.50 d.) 0.35 SUBMIT MY ANSWER g
Answer:
b.) 0.30
Step-by-step explanation:
15/50 = 0.3
When she graduates college, Linda will owe $43,000 in student loans. The interest rate on the federal loans is 4.5% and the rate on the private bank loans is 2%. The total interest she owes for one year was $1,585. What is the amount of each loan?
Answer:
federal loans = $29,000
private loans = $14,000
Step-by-step explanation:
x + y = 43000
.045x + .02y = 1585
x = 29,000
y = 14,000
Answer:
Amount of loan from federal : $ 29,000
Amount of loan from private bank : $ 14,000
Step-by-step explanation:
We know that Linda owes $43,000 in student loans. It is also given that the interest rate on the federal loans is 4.5%, while the interest rate on private loans is 2%, the total interest for a year being $1,585.
If Linda were to say own x dollars in federal loans, and y dollars in private loans, we know that she owns a total of $43,000, so -
x + y = 43,000
At the same time the loan interest amount is $1,585, while the interest rate on the federal loans is 4.5%, and the interest rate on private loans is 2%. The loans from each account will add to $1,585 -
0.045x + 0.02y = 1585
Let's solve the following system for x and y, the amount of each loan,
[tex]\begin{bmatrix}x+y=43000\\ 0.045x+0.02y=1585\end{bmatrix}[/tex] ( Substitute x = 43000 - y )
[tex]0.045\left(43000-y\right)+0.02y=1585[/tex] ( Simplify )
[tex]1935-0.025y=1585[/tex],
[tex]1935000-25y=1585000[/tex],
[tex]-25y=-350000[/tex],
[tex]y=14000[/tex],
[tex]x=29000[/tex]
Thus, the amount of loan from federal is $ 29,000 and the amount of loan from private bank is $ 14,000.
The circumference of the circle shown below is 75 inches. Which expression
gives the length in inches of DE?
D
A.
. 75
72
O B.
360
75
O C.
361
. 75
O D.
360
75%
Answer:
B. 360 .75
Step-by-step explanation:
The circumference of the circle is represented by π * diameter of the circle. The circumference of the circle is its perimeter. The circumference is arc length of the circle. The perimeter is curve length around the figure of the circle. The circumference of the circle of 75 inches is represented by 75/360.
Answer: 72/360 multiply by 75
Step-by-step explanation:
i just did this question
Find a polar equation r for the conic with its focus at the pole and the given eccentricity and directrix. (For convenience, the equation for the directrix is given in rectangular form.)
Conic: Parabola Eccentricity: e = 1 Directrix: y = 4
Answer:
The equation is [tex]r = \frac{4 }{ 1 + cos (\theta )}[/tex]
Step-by-step explanation:
From the equation we are told that
The Eccentricity: e = 1
The Directrix is y = 4
Generally the polar equation for e = 1 and y = + c is mathematically represented as
[tex]r = \frac{e * c }{ 1 + ecos (\theta )}[/tex]
So
[tex]r = \frac{1 * 4 }{ 1 + 1 * cos (\theta )}[/tex]
[tex]r = \frac{4 }{ 1 + cos (\theta )}[/tex]
what is a prime number
A number that can be divided exactly only by itself and 1.
For Eg:- 7, 10, 13.
Answer:
A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself. However, 4 is composite because it is a product (2 × 2) in which both numbers are smaller than 4. Primes are central in number theory because of the fundamental theorem of arithmetic:
Write each expression in a simpler form that is equivalent to the given expression. Let F be a nonzero number. f-4
Answer:
f-4
Step-by-step explanation:
f-4 cannot be simplified
This is the simplest form
Answer:
[tex]\large \boxed{f-4}[/tex]
Step-by-step explanation:
[tex]f-4[/tex]
[tex]\sf f \ is \ a \ nonzero \ number.[/tex]
[tex]\sf The \ expression \ cannot \ be \ simplified \ further.[/tex]
I need help with these questions asap, I will post pictures if you know them all answer them in the order of the photos from 1-5 thank you.
Answer:
1. step 4
2.idk
3. step 2
4.-5n = 1 ---------> n= -1/5
n + 15 = -10 -------> -25
n/5 = -1/5 ------> n = -1
n - 13 = -12 ------> n = 1
5. cant see the drop down menu or possible answers
but if an answer is the addition one thing
then the second one is the subtraction thing
Step-by-step explanation:
I NEED this answered within the next 30 minutes! Please it is simple. There is an error in this. What is it?
Answer:
(a). x = 80°
(b). x = 7.2 units
Step-by-step explanation:
Angle formed between the tangents from a point outside the circle measure the half of the difference of intercepted arcs.
(a). Here the intercepted arcs are,
Measure of major arc = 360° - 100°
= 260°
Measure of minor arc = 100°
x° = [tex]\frac{1}{2}[m(\text{Major arc})-m(\text{Minor arc})][/tex]
= [tex]\frac{1}{2}(260-100)[/tex]
x = 80°
(b). If a secant and tangent are drawn form a point outside the circle, then square of the measure of tangent is equal to the product of the measures of the secant segment and and its external segment.
x² = 4(4 + 9)
x² = 4 × 13
x² = 52
x = √52
x = 7.211 ≈ 7.2 units
In kickboxing, it is found that the force, f, needed to break a board, varies inversely with the length, l, of the board. If it takes 7 pounds of pressure to break a board that is 3 feet long, how long is a board that requires 5 pounds of pressure to break?
Answer:
4.2
Step-by-step explanation:
f varies inversly with L can be translated matimatically as:
● f = k/L
It takes 7 pounds of pressure to break a 3 feet long board.
Replace f by 7 and L by 3.
● 7 = k/3 => k=7×3=21
■■■■■■■■■■■■■■■■■■■■■■■■■■
Let's find tge length of a board that takes 5 pounds of pressure to be broken.
● 5 = k/L
● 5 = 21/L
● L = 21/5 = 4.2
So the board is 4.2 feet long
In a random sample of 205 people, 149 said that they watched educational television. Find the 95% confidence interval of the true proportion of people who watched educational television. Round intermediate answers to at least five decimal places.
Answer: Given a sample of 200, we are 90% confident that the true proportion of people who watched educational TV is between 72.1% and 81.9%.
Step-by-step explanation:
[tex]\frac{154}{200} =0.77[/tex]
[tex]1-0.77=0.23[/tex]
[tex]\sqrt{\frac{(0.77)(0.23)}{200} }[/tex]=0.049
0.77±0.049< 0.819, 0.721
If Company X has 1600 employees and 80% of those employees have attended the warehouse training course how many employees have yet to attend?
Answer:
320
Step-by-step explanation:
Total no of employees = 1600
% of employees attended the training = 80%
no. of employee who attended the training = 80/100* 1600 = 1280
No. of employees who are yet to attend the training = Total no of employees - no. of employee who attended the training = 1600-1280 = 320
Thus, 320 employees have yet to attend the training
Solve for x if 2(1+3x)=14
Answer:
x=2
Step-by-step explanation:
2(1+3x)=14
Divide each side by 2
2/2(1+3x)=14/2
1+3x = 7
Subtract 1 from each side
3x =7-1
3x = 6
Divide by 3
3x/3 = 6/3
x =2