Answer:
The p-value of the test is 0.0014 < 0.01, meaning that the data indicates that the true average unrestrained compressive strength is less than the design value of 3200.
Step-by-step explanation:
We want to determine whether the data indicate that the true average unrestrained compressive strength is less than the design value of 3200.
At the null hypothesis, we test if the mean is at the design value of 3200, so:
[tex]H_0: \mu = 3200[/tex]
At the alternate hypothesis, we test if it is less than the design value of 3200, so:
[tex]H_a: \mu < 3200[/tex]
The test statistic is:
[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, s is the standard deviation of the sample and n is the size of the sample.
3200 is tested at the null hypothesis:
This means that [tex]\mu = 3200[/tex]
The sample average unrestrained compressive strength for 50 specimens of a particular type of brick was computed to be 3120 psi, and the sample standard deviation was 180.
This means that [tex]n = 50, X = 3120, s = 180[/tex]
Test statistic:
[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]
[tex]t = \frac{3120 - 3200}{\frac{180}{\sqrt{50}}}[/tex]
[tex]t = -3.14[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a sample mean below 3120, which is the p-value of t = -3.14, using a one-tailed test, with 50 - 1 = 49 degrees of freedom.
With the help of a calculator, the p-value of the test is 0.0014
The p-value of the test is 0.0014 < 0.01, meaning that the data indicates that the true average unrestrained compressive strength is less than the design value of 3200.
Ms. Hall withdrew $20 from her checking account twice a week. Her total withdrawal amount when she last checked was -$220. How many weeks has she been doing this for?
Answer: five and a half weeks.
Step-by-step explanation: 20 times 2 (the twice a week deposit) = 40. 220 (the negative checking) divided by 40 (the deposits each week) equals 5.5
6. If radius is 18 am and an angle at center of circle
is 120 degrees, then the area of the sector is.......
A. 382.4 cm
B. 339.3 cm?
C. 350 cm2
D. 300 cm?
Answer:
Try A
Step-by-step explanation:
382.4cm
Write an exponential function in the form y=ab^xy=ab
x
that goes through points (0, 18)(0,18) and (2, 288)(2,288).
Answer:
[tex]y = 18*4^x[/tex]
Step-by-step explanation:
We want an exponential equation in the following format:
[tex]y = ab^x[/tex]
Point (0,18):
This means that when [tex]x = 0, y = 0[/tex]. So
[tex]y = ab^x[/tex]
[tex]18 = ab^0[/tex]
[tex]a = 18[/tex]
So
[tex]y = 18b^x[/tex]
Point (2,288):
This means that when [tex]x = 2, y = 288[/tex]. So
[tex]y = 18b^x[/tex]
[tex]18b^2 = 288[/tex]
[tex]b^2 = \frac{288}{18}[/tex]
[tex]b^2 = 16[/tex]
[tex]b = 4[/tex].
So
[tex]y = 18*4^x[/tex]
The radius of a sphere is 3 inches. Which represents the volume of the sphere? o 12pie cubic inches 36pie cubic inches O 64pie cubic inches 81pie cubic inches
Answer:
36 pie cubic inches
Step-by-step explanation:
Use the formula: [tex]V = \frac{4}{3} \pi r^{3}[/tex]
Plug in the value for radius and solve:
[tex]V = \frac{4}{3} \pi 3^{3}[/tex]
Becuase of the nature of the answer options, you only have to solve to a certain point: [tex]V = 36 \pi[/tex]
A triangle has base 4 cm
and height 9 cm, What is its
area
Answer:
18 cm^2
Step-by-step explanation:
Formula for area of triangle: bh/2
4x9=36
36/2=18
Rectangle ABCD is shown on the grid. What is the area of rectangle ABCD in square units? 6 O 3V17 square units B (3, 3) O 6/17 square units O 17 square units O 34 square units 6-5-4-3-2-11 3 4 5 6 X -3 C (1.-5)
Answer: b is correct
Step-by-step explanation: i did this
The area of rectangle ABCD is 34 square unit.
What is Distance Formula?In a cartesian plane there are two coordinates as P(a, b) and Q(c, d) then the distance between these points are
PQ = √(c- a)² + (d- b)²
We have Coordinates of rectangle
A(-1, 4), B(3, 3), C(1, -5) and D(-3, -4)
Using Distance Formula
AB = √ (3-4)² + (3+1)²
AB = √1 + 16
AB = √17 unit
Now, CB = √(-5-3)² + (1-3)²
CB= √ 64 + 4
CB = √68
CB = 2√17 unit
So, the area of Rectangle ABCD is
= l w
= √17 x 2√17
= 2 x 17
= 34 square unit
Learn more about Distance Formula here:
https://brainly.com/question/25841655
#SPJ7
Un aserradero adquiere maquinaria y equipo para el corte de madera, que va perdiendo valor conforme transcurren los años, hasta que su valor contable es cero, como indica la gráfica de la función D(x)=(-x^3+2x^2+20x+20)/(x^2+4x+4) que modela esta depreciación en el eje y cada unidad son 20 000 pesos y en el eje x cada unidad es de 3 años.
a) ¿Cuál es el valor inicial del equipo y herramienta? ¿cuánto se ha depreciado al cabo de 12 años?
b) ¿existe un modelo lineal que aproxime los mismos valores que la función D(x)?
c) ¿En cuánto difieren los valores de ambas funciones al cabo de 9 años?
Answer:
-1 5
Step-by-step explanation:
solve the inequality
Answer:
x<3
Step-by-step explanation:
4x-7<5
4x<5+7
4x<12
x<3
what is a valid inference
Answer:
Deduction is inference deriving logical conclusions from premises known or assumed to be true, with the laws of valid inference being studied in logic. Induction is inference from particular premises to a universal conclusion.
Step-by-step explanation:
The ages of customers in a shoe store at exactly two in the afternoon are shown in the stem and leaf plot below. Customers' Ages How many customers are under the age of 40? A. 15 B. 16 C. 10 D. 3
Answer:
A
Step-by-step explanation:
The time married men with children spend on child care averages 6.4 hours per week (Time, March 12, 2012). You belong to a professional group on family practices that would like to do its own study to determine if the time married men in your area spend on child care per week differs from the reported mean of 6.4 hours per week. A sample of 40 married couples will be used with the data collected showing the hours per week the husband spends on child care. The sample data is contained in the Excel Online file below. Construct a spreadsheet to answer the following questions.
Complete question :
The time married men with children spend on child care averages 6.4 hours per week (Time, March 12, 2012). You belong to a professional group on family practices that would like to do its own study to determine if the time married men in your area spend on child care per week differs from the reported mean of 6.4 hours per week. A sample of 40 married couples are surveyed to collect the hours per week the husband spends on child care. The sample mean is 7.0 hours per week, and the sample standard deviation is 2.4276 hours per week. Use Excel to answer the following questions. a. What are the hypotheses if your group would like to determine if the population mean number of hours married men are spending in child care differs from the mean reported by Time in your area? b. What is the test statistics of the population mean? c. Using a .05 level of significance, what are the critical values? d. What is your conclusion?
Answer:
H0 : μ = 6.4
H1 : μ ≠ 6.4
Test statistic = - 1.563
Critical value = ±2.023
Fail to reject the null ; there is no significant evidence to support the claim that mean number of hours spent differs
Step-by-step explanation:
H0 : μ = 6.4
H1 : μ ≠ 6.4
Test statistic, Z :
(Xbar - μ) / (s/√n)
(6.4 - 7) / (2.4276/√40)
-0.6 / 0.3838372
T= -1.563
α = 0.05 ; df = n - 1 = 40 - 1 = 39
Critical value(0.05, 39) = ±2.023
|T| > +Tcritical ; Reject the Null
Since |T| < +Tcritical ; then we fail to reject the Null, hence, we conclude that there is no significant evidence to support the claim that mean number of hours spent by married men in child care differs.
i don’t know if it’s B or C what do you guys think?
Answer:
I think it is D.
Step-by-step explanation:
It is a guess, but I am not fully sure.
If correct, may I have a brainliest?
XxRoadToAcexX
Answer:
D) 17.51
Step-by-step explanation:
D) 17.51
How many more barrels of gasoline then diesel were produced last year
Answer:
3,000,000
Step-by-step explanation:
please answer this as quick as possible.
Answer:
False
x=8-10=-2
Step-by-step explanation:
[tex]10 = x - 8 \\ ➡ \: x = 10 + 8 \\ ➡ \: x = 18[/tex]
[tex]\sf\red{The\:value\:of\:x\:is\:18.\:}[/tex]
[tex]\sf\pink{Hence,\:it\:is\:false.}[/tex]
[tex]\circ \: \: { \underline{ \boxed{ \sf{ \color{green}{Happy\:learning.}}}}}∘[/tex]
In a basketball game, Ellen scores 20 more points than Kevin, and Kevin scores three times as many points as Bob. If 48 points were scored in total by these three players, how many points did Kevin score?
middle school math (05.02)The area of the parallelogram below is square meters. 6 m 8 m 2 m Numerical Answers Expected! (Picture included)
Find the area of the shaded region to the nearest tenth
Answer:
B. A = 119.1 in.²
Step-by-step explanation:
A = area of trapezoid - area of circle
A = ½(b1 + b2)h - πr²
A = [½(27 + 12)(14) - 3.14159(7²)] in.²
A = 119.1 in.²
Gail bought 7/8 pound of cheese and Jose bought 1/3 pound of cheese. How much more cheese did Gail buy than Jose?
Answer:
7/8 * 3 = 21/24
1/3 * 8 = 8/24
21-8 = 13
Gail bought 13/24 pound more than Jose
What is the slope of the following table?
Answer:
slope: 5/2
Step-by-step explanation:
1. AIDS is caused by a virus called HIV. True or false
Answer:
[tex]\huge\boxed{True\hookleftarrow}[/tex]
⎆ AIDS (Acquired Immunodeficiency Syndrome) is caused by a virus named HIV (Human Immunodeficiency Virus). This disease can be transmitted through :-1) sexual contact2) transfer of blood etc.Find the 8th term in the
sequence
-1/2,-1, -2, -4,...
Hint: Write a formula to help you.
1st term . Common Ratio desired term – 1)
Answer:
-64
Step-by-step explanation:
By looking at the numbers, we can identify that this is a geometric sequence and the ratio would be 2. The formula to find the nth term in a geometric series is:
[tex]t *r^{n-1}[/tex]
where t is the first term and r is the ratio. We can substitute in the information we know:
[tex]-\frac{1}{2} *2^{n-1}[/tex]
We are looking for the eighth term, so we substitute 8 where n is:
[tex]-\frac{1}{2}*2^{8-1}[/tex]
We can simplify:
[tex]-\frac{1}{2}*2^7[/tex]
[tex]-2^6[/tex]
[tex]-64[/tex]
Can anyone help me out here !
Write an equation of the circle with center (3,-2) and radius 11.
let h= 3, k=-2
radius (r) = 11 ,then
(x-h)^2 + ( y-k)^2 = r^2
(x-3)^2 + ( y+2)^2 = 11^2
x^2 -6x +9 + y^2 +4y +4 = 121
x^2 + y^2 - 6x +4y -108 = 0 is the required eq
Which expression is equivalent to -51 - (-60)?
Choose 1 answer:
А
-60 +(-51)
В.
-51 +60
51 - 60
60 + 51
2 of 4
How many times can you fill a 250ml cup from a 4 litre jar?
3/4(x-2)+1/3(2x+5)=4
Answer:
X=86/17
Step-by-step explanation:
Answer:
x=46/17
Step-by-step explanation:
Let's solve your equation step-by-step.
3/ 4 (x−2)+ 1/ 3 (2x+5)=4
Step 1: Simplify both sides of the equation.
3/ 4 (x−2)+ 1/ 3 (2x+5)=4
( 3/ 4 )(x)+( 3/ 4 )(−2)+( 1/ 3 )(2x)+( 1/ 3 )(5)=4 (Distribute)
3/ 4x+ −3/ 2 + 2/ 3 x+ 5/ 3 =4
( 3/ 4 x+ 2/ 3 x)+( −3/ 2 + 5/ 3 )=4 (Combine Like Terms)
17/ 12 x+ 1/ 6 =4
17/ 12 x+ 1/ 6 =4
Step 2: Subtract 1/6 from both sides.
17/ 12 x+ 1/ 6 − 1/ 6 =4− 1/ 6
17/ 12 x= 23/ 6
Step 3: Multiply both sides by 12/17.
( 12/ 17 )*( 17/ 12 x)=( 12/ 17 )*( 23/ 6 )
x= 46/ 17
HELP WILL MARK BRAINLIEST
D 75.4 cm2
24. What is the surface area of the given sphere?
12 cm
A 48 cm2
B 1441 cm
C 5767 cm
D 23041 cm2
PLEASE HELP ITS URGENT Select the correct answer.
Which document do you need to have on hand when preparing to file your tax return ?
Answer:
a it's birth certificate
For which of the following is x=-5 a solution? Select all that apply.
A) x+10=-5
B) -x^2+50=25
C) |2x|=10
D) x<0
E) 2x<10
Answer:
B
D
E
[tex]b. - ( - 5)^{2} + 50 = 25 \\ \\ d. \: - 5 < 0 \\ \\ e. \: 2( - 5) < 10[/tex]
Answer:
B and C
Step-by-step explanation:
Those 2 are the only ones that equal 5,-5