Answer:
A placebo is a useless substance that takes the place of an actual drug
Step-by-step explanation:
This is to test to see if the drug actually does anything, or if the patients are really just deceived by their imagination
5. Which is equivalent to 1/2
? Select all that apply.
A sin 30°
B sin 45°
C cos 45°
D cos 60°
E tan 30°
F tan 45º
Answer:
A sin 30°D cos 60°Step-by-step explanation:
Attached is a short table of trig function values. There are really only three you need to remember if you keep an image of the sine and cosine graphs in your head (for 0° and 90° values).
sin(α) = cos(90°-α)
tan(α) = sin(α)/cos(α)
__
sin(30°) = cos(60°) = 1/2 . . . . . . . the answer to this question
sin(45°) = cos(45°) = 1/√2 = (√2)/2
sin(60°) = cos(30°) = (√3)/2
__
I find it just as easy to remember SOH CAH TOA and the side ratios in isosceles and half-equilateral right triangles: 1:1:√2 and 1:√3:2, respectively.
Joel had 4 liters of water. He drank 2.7 liters of water while he was hiking. How many liters does Joel have left?
Answer:
1.3 liters are left
Step-by-step explanation:
Take the amount of water he had and subtract the amount of water he drank
4.0
-2.7
-----------
Borrow
3.10
-2.7
-----------
1.3 liters are left
Answer:
1.3 liters
Step-by-step explanation:
In the given question: "Joel had 4 liters of water, and drank 2.7 liters of water while he was hiking. "
Subtract the total before the hike by the amount he drank during the hike.
[tex]4-2.7=1.3[/tex]
Joel should have 1.3 liters left.
How many pieces of tape 5mm long can be cut from a piece 15cm long ?
Answer:
A piece of tape: 15cm =150mm
=> The number of tape 5mm that could be cut: N = 150/5 = 30
Hope this helps!
:)
The mean SAT score in mathematics, M, is 600. The standard deviation of these scores is 48. A special preparation course claims that its graduates will score higher, on average, than the mean score 600. A random sample of 70 students completed the course, and their mean SAT score in mathematics was 613.
a) At the 0.05 level of significance, can we conclude that the preparation course does what it claims? Assume that the standard deviation of the scores of course graduates is also 48.
Answer:
Step-by-step explanation:
The mean SAT score is [tex]\mu=600[/tex], we are going to call it \mu since it's the "true" mean
The standard deviation (we are going to call it [tex]\sigma[/tex]) is
[tex]\sigma=48[/tex]
Next they draw a random sample of n=70 students, and they got a mean score (denoted by [tex]\bar x[/tex]) of [tex]\bar x=613[/tex]
The test then boils down to the question if the score of 613 obtained by the students in the sample is statistically bigger that the "true" mean of 600.
- So the Null Hypothesis [tex]H_0:\bar x \geq \mu[/tex]
- The alternative would be then the opposite [tex]H_0:\bar x < \mu[/tex]
The test statistic for this type of test takes the form
[tex]t=\frac{| \mu -\bar x |} {\sigma/\sqrt{n}}[/tex]
and this test statistic follows a normal distribution. This last part is quite important because it will tell us where to look for the critical value. The problem ask for a 0.05 significance level. Looking at the normal distribution table, the critical value that leaves .05% in the upper tail is 1.645.
With this we can then replace the values in the test statistic and compare it to the critical value of 1.645.
[tex]t=\frac{| \mu -\bar x |} {\sigma/\sqrt{n}}\\\\= \frac{| 600-613 |}{48/\sqrt(70}}\\\\= \frac{| 13 |}{48/8.367}\\\\= \frac{| 13 |}{5.737}\\\\=2.266\\[/tex]
since 2.266>1.645 we can reject the null hypothesis.Answer:
The null hypothesis is that the SAT score is not significantly different for the course graduates.
Alternate hypothesis: there is a significant difference between the SAT score achieved by the course graduates as compared to the non-graduates.
Apply the t-test. The Test Statistic value comes out to be t = 1.738 and the p-value = 0.0844
Since the p-value is larger than 0.05, the evidence is weak and we fail to reject eh null hypothesis.
Hope that answers the question, have a great day!
1f 3/4 gallon of paint can cover 1/8 of the fence how many gallons will he need to paint the whole fence
Answer:
He will need 6 gallons of painting to paint the whole fence.
Step-by-step explanation:
Since 3/4 gallon of paint covered 1/8 of the fence, we have to multiply 3/4 by 8 in order to find the number of gallons that will paint the whole fence (because 8 x 1/8 = 1)
[tex]\frac{3}{4}[/tex] x [tex]\frac{8}{1}[/tex] = [tex]\frac{24}{4}[/tex] = 6
Hope this helps!
If you bought a stock last year for a price of $141,and it has risen 1.8% since then,
how much is the stock worth now, to nearest cent?
Answer:
Current worth of stock is $141.538
Current worth of stock rounded to nearest cent is $142
Step-by-step explanation:
price of stocks= $141
percentage increase in price of stocks = 1.8% of initial price of stock
dollar value increase in price of stocks = 1.8% of initial price of stock
increase in price of stocks = 1.8% of $141
increase in price of stocks = 1.8/100 * $141 =$ 253.8/100 = $2.538
Current worth of stock = initial price of stock+increase in price of stocks
substituting the value of initial price of stock and increase in price of stocks we have
Current worth of stock =$141 + $2.538 = $141.538
Since we need to find stock worth now, to nearest cent, as after decimal there .5 and any value greater than or equal to .5 is rounded to one then after rounding, $141.538 becomes $142
what is the equation of a straight line is parallel to y = 4x-1?
Answer: i dont know
Step-by-step explanation:
Two models of the same compound are shown.

In what way is Model A better than Model B?
Model A shows the types of elements in the compound, but Model B does not.
Model A shows the total number of atoms in the molecule, but Model B does not.
Model A shows the three-dimensional shape of the molecule, but Model B does not.
Model A shows the number of atoms of each element in the molecule, but Model B does not.
Answer:
Step-by-step explanation:
Model B shows how the atoms in the molecule are connected, but Model A does not.
it is C
just did the test
There is a bag filled with 3 blue, 4 red and 5 green marbles.
A marble is taken at random from the bag, the colour is noted and then it is replaced.
Another marble is taken at random.
What is the probability of exactly 1 red?
Answer:
22.22%
Step-by-step explanation:
If it is exactly a red, it means that it is removed on the first or second attempt, but only once, in this case it does not matter if it is on the first or second attempt because the marble is returned to the bag.
So suppose that on the first attempt red is drawn, the probability would be:
4 / (3 + 4 + 5) = 4/12 = 1/3
Now, on the second attempt, it is not to draw a red, it must be green or blue, so it would be:
(5 + 3) / (3 + 4 + 5) = 8/12 = 2/3
The final probability then is:
1/3 * 2/3 = 0.2222
that is, the probability is 22.22%
In ΔQRS, q = 1.3 inches, r = 1.6 inches and ∠S=157°. Find the length of s, to the nearest 10th of an inch.
Answer:
2.8
Step-by-step explanation:
using cosine rule
[tex]s^{2}[/tex] = [tex]1.3^{2} + 1.6^{2} - 2(1.3)(1.6)cos 157[/tex]
s = [tex]\sqrt{8.0793}[/tex] = 2.842 = 2.8
Rewrite in logarithmic form 19^2 = 361
Answer:
[tex]\log_{19}{361}=2[/tex]
Step-by-step explanation:
We know that taking logarithms performs the transformation ...
[tex]b^e=x\\\\e\cdot\log{b}=\log{x}\quad\text{take logs}\\\\e=\dfrac{\log{x}}{\log{b}}\quad\text{divide by $\log{b}$}\\\\\log_b{x}=e\quad\text{use the change of base formula}[/tex]
Then for b=19, e=2, x=361, we have
[tex]\boxed{\log_{19}{361}=2}[/tex]
Check all of the expressions that are equal to the one below.
(8 + 7). 11
A. 11. (8 + 7)
B. 8•(11)-7•(11)
C. 11•(7) + 11 (8)
D. 8+ (711)
Answer:
A. 11•(8 + 7)
B. 8•(11)-7•(11)
C. 11•(7) + 11•(8)
Step-by-step explanation:
The commutative property of multiplication lets you swap the order of the factors in the product:
(8 +7)•11 = 11•(8 +7)
The distributive property lets you eliminate parentheses:
(8 +7)•11 = 8•11 +7•11
And the commutative properties of addition and multiplication let you rearrange this sum of products to ...
(8 +7)•11 = 11•7 +11•8
The__ of a circle centered at the origin measures the distance from the origin to any point on the circle.
Answer:
the radius
Step-by-step explanation:
Answer:
radius
Step-by-step explanation:
Find number x, if when you add 7 to it and double the result you get 19 more than x.
NEED HELP ASAP
Answer:
x = 5.
Step-by-step explanation:
We can set up equivalent equations like this to solve:
2(x + 7) = x + 19
Distribute the 2, giving us:
2x + 14 = x+ 19
Move the variables to one side, and the numbers to the other, giving us:
x = 5
Write the contrapositive of the conditional statement. Determine whether the contrapositive is true or false. If it is false, find a counterexample.
Two angles measuring 180 are supplementary.
Answer: A converse statement is formed by exchanging the hypothesis and conclusion of the conditional.
Step-by-step explanation:
Find the surface area of the triangular prism shown below. 5x6x7
Answer:
5 times 6 is 30 and 30 times 7 is 210
so 210 is your anser hop that helps
Answer:
210
Step-by-step explanation: First way: 5x6=30x7=210
2nd way/distributive property: 5(6x7) 5(6=30x7=210.
Solve the equation and express each solution in a + bi form.
x - 7² – 8=0
Answer:
x + 57i
Step-by-step explanation:
x - 7² – 8=0
x -49-8
x - 57 = x + 57(-1) ; i = -1( complex number notation)
x + 57i
t(x) = ax^5 + 2 where is a real number. If the points (-2, 66) and (2, -62) are on the graph of the function classify as one of the following.
0 < a < 1
a < -1
a > 1
0 > a > -1
Answer:
a < -1
Step-by-step explanation:
Okay, so we are given this equation:
t(x) = ax^5 + 2
Lets plug in -2 as x and see what happens.. t(x) can be 66..
[tex]a * (-2)^{5} + 2[/tex] = 66
-32a + 2 = 66
-32a = 64
a = -2
A is less than -1,
a < -1
Select the correct answer.
Consider the given solids with the dimensions shown. Which solids are similar?
three triangular prisms. Figure 1 has a right triangle base that is 9 meters by 12 meters and a height of 16 meters, figure 2 has a right triangle base that is 12 meters by 16 meters and a height of 18 meters, and figure 3 has a right triangle base that is 36 meters by 48 meters and a height of 64 meters.
Figures not drawn to scale
A.
only figure 1 and figure 2
B.
only figure 2 and figure 3
C.
only figure 1 and figure 3
D.
all three figures
E.
none of the figures
Answer:
Only Figure 1 and Figure 3 Are Similar.
Step-by-step explanation:
Figure 1 and Figure 3 are proportional by 1:4 while the Figure 2 is not proportional to any of them.
Multiple choices answer and explain the solution?
Answer:
associative property of multiplication
Step-by-step explanation:
You cant rlly explain, you just have to know your properties
a.756
b.936
c.1,008
d.1,080
HELLLPPPPP
Answer:
936 is the correct option
Step-by-step explanation:
calm down !!!we know that the volume of cuboid is l×b×h=10×(10-2)×9=10×8×9=720now again the volume of cuboid (bottom) is l×b×h=12×9×2=216the total volume is cuboid(up) + cuboid (bottom)=720+216=936 which is bSOMEONE PLEASE HELP ???
Which of the following proportionality statements is correct ?
Answer:
The third one is correct
Step-by-step explanation:
Suppose an airline claims that its flights are consistently on time with an average delay of at most 15 minutes. It claims that the average delay is so consistent that the variance is no more than 150 minutes. Doubting the consistency part of the claim, a disgruntled traveler calculates the delays for his next 25 flights. The average delay for those 25 flights is 22 minutes with a standard deviation of 15 minutes. A chi-square test was performed. Graph the situation. Label and scale the horizontal axis. Mark the mean and test statistic. Shade the p-value.
Answer:
The p-value will be "0.0549".
Step-by-step explanation:
The given values are:
Time, t = 15 minutes
Df, σ = 25-1 = 24
Now,
⇒ [tex]H_{0}:\sigma^2\leq 150[/tex]
and,
⇒ [tex]H_{1}:\sigma^2>150[/tex]
As we know,
Chi square = [tex]\frac{(n-1)s^2}{(\sigma^2)}[/tex]
On putting the values in the above formula, we get
⇒ = [tex]\frac{24\times 15^2}{150}[/tex]
⇒ = [tex]\frac{24\times 225}{150}[/tex]
⇒ = [tex]36[/tex]
Therefore, p-value = 0.0549
The p-value determined > 0.05, the null hypothesis also isn't dismissed at point 0.05.
AB=6CM AC= 12cm
calculate the length of CD
AB=6cm AC=12cm
AC² = AB + BC²
12² = 6² + CB²
CB² = 12² - 6²
CB² = 144 - 36
CB² = 108
CB = √ 108 cm.
sin 55° = CB / CD
0.81915 = √108 / CD
CD = 10.392 / 0.81915
CD = 12.686 cm
Answer:
Step-by-step explanation:
This was a question on mathswatch, so I’ve done this.
You need to round to 3 significant numbers
AB=6cm AC=12cm
AC² = AB + BC²
12² = 6² + CB²
CB² = 12² - 6²
CB² = 144 - 36
CB² = 108
CB = √ 108 cm.
sin 55° = CB / CD
0.81915 = √108 / CD
CD = 10.392 / 0.81915
CD = 12.686 cm
CD = 12.7 cm
A video company randomly selected 100 of its subscribers and asked them how many hours of shows they watch per week. Of those surveyed 35 watch more than 10 hours per week. Based on the data, if the company has 3,000 subscribers, how many watch more than 10 hours per week?
Hello there!
35/100 watch more then 10 hours a week
3000 is 30 times greater than 100 so we can simply multiply 35/100 by 30.
35/100 x 30 = 1050/3000
Therefore, if the company had 3,000 subscribers, 1,050 subscribers would be watching more than 10 hours a week.
a =4
5
b =3
2
Work out a - 2b as a column vector.
Answer:
[-2; 1 ] is the new column vector
Step-by-step explanation:
See explanation in the attachment.
The value of a-2b as a column vector is [tex]\left[\begin{array}{c}-2&1\end{array}\right][/tex] .
What is a matrix?A matrix is an arrangement of numbers, expressions or symbols arranged in rows and columns as a rectangular array. These rows and columns define the size or dimension of a matrix.
For the given situation,
The matrix is
[tex]a=\left[\begin{array}{c}4&5\end{array}\right][/tex] , [tex]b=\left[\begin{array}{c}3&2\end{array}\right][/tex]
The operation is a - 2b. The matrix becomes
⇒ [tex]a-2b=\left[\begin{array}{c}4&5\end{array}\right] -2\left[\begin{array}{c}3&2\end{array}\right][/tex]
⇒ [tex]a-2b=\left[\begin{array}{c}4&5\end{array}\right] -\left[\begin{array}{c}6&4\end{array}\right][/tex]
⇒ [tex]a-2b=\left[\begin{array}{c}-2&1\end{array}\right][/tex]
Hence we can conclude that the value of a-2b as a column vector is [tex]\left[\begin{array}{c}-2&1\end{array}\right][/tex] .
Learn more about matrices here
https://brainly.com/question/18291235
#SPJ3
ASAP! GIVING BRAINLIEST! Please read the question THEN answer correctly! No guessing. Show your work or give an explaination.
Answer:
B. [tex]f(x)=-(x-4)^{2} -3[/tex]
Step-by-step explanation:
[tex]f(x)=x^{2}[/tex]
The transformations are:
Reflected upon the x axis (x is now negative):
[tex]f(x)=-x^{2}[/tex]
Moved 4 units to the right (instead of just the variable x, you have (x-4)):
[tex]f(x)=-(x-4)^{2}[/tex]
And finally moved 3 units down (so now it's minus 3):
[tex]f(x)=-(x-4)^{2} -3[/tex]
Hope this helps! :]
Working alone, Dan can sweep a porch in
15 minutes. Alberto can sweep the same
porch in 11 minutes. If they worked
together how long would it take them?
Answer:
It will take them 6.35 minutes
Step-by-step explanation:
The question can be solved when you know how much of the job can be done in minutes.
Therefore if Dan can do the job in 15 minutes he will be to sweep 1/15 of the porch in 1 minutes. Alberto can do the same job in 11 minutes, in 1 minutes he will do 1/11 of the job.
let
a = combined time together
1/15 + 1/11 = 1/a
(11 + 15)/165 = 1/a
26/165 = 1/a
cross multiply
26a = 165
divide both sides by 26
a = 165/26
a = 6.34615384615
a ≈ 6.35 minutes
It will take them 6.35 minutes
In ΔHIJ, the measure of ∠J=90°, HI = 6.6 feet, and IJ = 2.9 feet. Find the measure of ∠H to the nearest degree.
Answer:
26
Step-by-step explanation:
Answer:
26
Step-by-step explanation:
sinH= hypotenuse/opposite = (2.9/6.6)
H = sin^-1 ( 2.9/6.6)
H=26.065≈26
2 people can paint a fence in one hour, how long would it take 10 people, give your answer in minutes
Answer:
5 hours=300minutes
Step-by-step explanation:
10/2=5 hours
To find the answer in minutes do
50*60 becuase there are 60 minutes in 1 hour.
5*60=300min
Answer:
12 minutes
Step-by-step explanation:
2 people=60 minutes
÷2 ×2
1 people=120 minutes
×10 ÷10
10 people=12 minutes