What are the answers to questions one and three
Answer:
1) x=2, x=-2; 3) x=8/3
Step-by-step explanation:
Use the quadratic formula: -b+-sqrtb^2-4ac/2a
Make y 0 to find the x intercept
A researcher compares the effectiveness of two different instructional methods for teaching electronics. A sample of 138 students using Method 1 produces a testing average of 61. A sample of 156 students using Method 2 produces a testing average of 64.6. Assume the standard deviation is known to be 18.53 for Method 1 and 13.43 for Method 2. Determine the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2. Step 1 of 2: Find the critical value that should be used in constructing the confidence interval.
Answer:
The 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).
Step-by-step explanation:
The (1 - α)% confidence interval for the difference between population means is:
[tex]CI=(\bar x_{1}-\bar x_{2})\pm z_{\alpha/2}\times \sqrt{\frac{\sigma^{2}_{1}}{n_{1}}+\frac{\sigma^{2}_{2}}{n_{2}}}[/tex]
The information provided is as follows:
[tex]n_{1}= 138\\n_{2}=156\\\bar x_{1}=61\\\bar x_{2}=64.6\\\sigma_{1}=18.53\\\sigma_{2}=13.43[/tex]
The critical value of z for 98% confidence level is,
[tex]z_{\alpha/2}=z_{0.02/2}=2.326[/tex]
Compute the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 as follows:
[tex]CI=(\bar x_{1}-\bar x_{2})\pm z_{\alpha/2}\times \sqrt{\frac{\sigma^{2}_{1}}{n_{1}}+\frac{\sigma^{2}_{2}}{n_{2}}}[/tex]
[tex]=(61-64.6)\pm 2.326\times\sqrt{\frac{(18.53)^{2}}{138}+\frac{(13.43)^{2}}{156}}\\\\=-3.6\pm 4.4404\\\\=(-8.0404, 0.8404)\\\\\approx (-8.04, 0.84)[/tex]
Thus, the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).
Estimate by rounding the first number to the nearest ten and the second number to the nearest hundred. 19 Х 307 II ? Х ? = ?
Answer:
6,200
Step-by-step explanation:
19-20
307-310
310 x 20= 6,200 or 20 x 310= 6,200
How many pounds of a 15% copper alloy must be mixed with 700lb of a 30% copper alloy to maybe a 25.5% copper alloy
Answer:
[tex]300\; \rm lb[/tex].
Step-by-step explanation:
Let [tex]x[/tex] represent the mass (in pounds) of that [tex]15\%[/tex] copper alloy required, such that the final mixture would contain [tex]25.5\%[/tex] copper by mass.
Consider: if [tex]x[/tex] pounds of that [tex]15\%[/tex] copper alloy is mixed with [tex]700[/tex] pounds that [tex]30\%[/tex] copper alloy, what would be the mass of copper in the mixture?
Mass of copper in [tex]x[/tex] pounds of that [tex]15\%[/tex] copper alloy: [tex](0.15\, x)\; \rm lb[/tex].Mass of copper in [tex]700[/tex] pounds of that [tex]30\%[/tex] copper alloy: [tex]700 \times 0.30 = 210\; \rm lb[/tex].Therefore, the mixture would contain [tex](210 + 0.15\, x) \; \rm lb[/tex] of copper.
The mass of that mixture would be [tex](700 + x)\; \rm lb[/tex]. The mass fraction of copper in that mixture would be:
[tex]\displaystyle \frac{(210 + 0.15\, x)\; \rm lb}{(700 + x)\; \rm lb} \times 100\%[/tex].
This ratio is supposed to be equal to [tex]25.5\%[/tex]. These two pieces of equations combine to give an equation about [tex]x[/tex]:
[tex]\displaystyle \frac{(210 + 0.15\, x)\; \rm lb}{(700 + x)\; \rm lb} \times 100\% = 25.5\%[/tex].
[tex]\displaystyle \frac{210 + 0.15\, x}{700 + x} = 0.255[/tex].
Simplify and solve for [tex]x[/tex]:
[tex]210 + 0.15\, x= 0.255\, (700 + x)[/tex].
[tex](0.255 - 0.15)\, x= 210 - 0.255 \times 700[/tex].
[tex]\displaystyle x = \frac{210 - 0.255 \times 700}{0.255 - 0.15} = 300[/tex].
Therefore, [tex]300\; \rm lb[/tex] of that [tex]15\%[/tex] alloy would be required.
A line passes through the points (3, -2) and (5, 2). Which is the equation of the line?
a
y = negative one-half x + 1
b
y = one-half x + 7
c
y = 2x + 6
d
y = 2x – 8
Option D : y= 2x-8 is the line passing through the given points
If m angle P = 85', which is a possible measure for Y?
OMZY = 80°
OmZY = 85°
OmZY = 100°
OmZY = 180°
Answer:c
Step-by-step explanation:
100° is a possible measure for m∠Y.
Hence, Option C is the correct option.
What is mean by Triangle?A triangle is a three sided polygon, which has three vertices and three angles which has the sum 180 degrees.
Given that,
In triangles ΔXYZ and ΔMPN
XY = MP and YZ = PN
XY=23 in. and MN=19 in.
Clearly
XY > MN
⇒ m ∠Y > m ∠P ...( since angle opposite to the greater side is greater )
And m ∠P = 85° ⇒ m ∠Y > 85°
Hence,
option (1) and option (2) are not correct as they are less than 85°.
Option 4 is also not correct as it cannot be possible in a triangle because 180° is the angle of a straight line.
Therefore, Option 3 should be the correct option correct option, 100° is a possible measure for m ∠Y.
Learn more about the triangle visit;
brainly.com/question/1058720
#SPJ7
Consider the graph of function f below.
The function g is a transformation of f. If g has a y-intercept at -1, which of the following functions could represent g?
A. g(x) = f(x) + 4
B. g(x) = f(x) - 1
C. g(x) = f(x + 4)
D. g(x) = f(x - 1)
A gene is composed of two alleles. An allele can be either dominant or recessive. suppose that a husband and a wife who are both carriers of the sickle-cell anemia allele but do not have the disease, decide to have a child. because both parents are carriers of the disease, each one has a dominant normal cell allele (S), and one recessive sickle-cell allele (s). Therefore the genotype of each parent is Ss. Each parent contributes one allele to his or her offspring with each allele being equally likely.
a.List the possible genotypes of their offspring.
b. what is the probability that the offspring will have sickle cell- genotype ss?
c. what is the probability that the offspring will not have sickle cell but still be a carrier (one normal cell allele and one sickle cell allele)
Answer:
a) SS, Ss, ss
b) 1/4
c) 1/2
Step-by-step explanation:
According to this question, a gene coding for possession or not of sickle cell has two alleles. Allele "S" codes for normal cell while allele "s" codes for sickle cell. A heterozygous individual or carrier will have a "Ss" genotype.
If two carriers of the sickle cell condition decide to have a child and mate i.e. Ss × Ss, the following gametes will be produced by each parent: S and s.
a) Using these gametes (S, s) in a punnet square (see attached image), the four possible offsprings with the following genotypes will be produced: SS, Ss and ss in a GENOTYPIC RATIO 1:2:1.
b) Since offsprings with the genotype "ss" will possess the sickle cell condition/phenotype, the probability of offsprings that will have sickle cell is 1/4 i.e. 1 out of 4 possible offsprings
c) Also,carrier genotype will be "Ss", therefore, the probability that the offspring will not have sickle cell but still be a carrier (one normal cell allele and one sickle cell allele) will be 2/4 or 1/2 i.e. 1 out of 2 possible offsprings.
How would I do this
Answer:
15
Step-by-step explanation:
Since the two triangles are similar you can use the ratio 6/9 = 10/x. Then you would cross multiply. 6x=90. 90/6=15. So the answer is 15
PLEASE HELP NOWWW!!!!!! A country consists of two islands. The population of birds on one island is 1.105 million, and the population of birds on the other island is 2.21 million. Which expression finds the population of birds for this country?
1. 1.105 million + 2.021 million
2. 1.15 million + 2.21 million
3. 1.105 million + 2.201 million
4. 1.105 million + 2.210 million
the answer is 1.. I know this because im in seventh grade
Answer:
It's D
Step-by-step explanation:
I did the same thing.
sorry if this doesn't help!! I tried..
find the difference between 20 and the sum of 10 and 3
Answer:
The answer is 7
10 + 3 = 13
20 - 13 = 7
Someone answer for angle 1 pls
Answer:
120 degrees
Step-by-step explanation:
5 times 25 equals 125.
subtract 5
=120
Answer:
Angle 1 = 120°
Angle 2 = 60°
if you add both of em up, they equal to 180°.
Step-by-step explanation:
5(25)-5
125-5
120
2(25)+10
50+10
60
;)))))))))))))))))))))))))))))))))))))))))))))))
Answer:
;)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
Step-by-step explanation:
yes yes do the ;))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
PLEASE HELP ME OUT!!!
Luna's retirement party will cost $630 if she invites 21 guests. What is the maximum number of guests there can be if Luna can afford to spend a total of $780 on her retirement party? Assume the relationship is directly proportional.
Answer:
The maximum number of guests for $780 would be 26.
Step-by-step explanation:
Write and solve an equation of ratios. In the first column write $630/$780; in the right column write 21/x:
630 21
---------- = -------
780 x
Cross-multiplying, we get 630x = 21(780), which yields x = 26.
The maximum number of guests for $780 would be 26.
What is the volume of this figure
Answer:
875 cubic feet
Step-by-step explanation:
10x5x5=250
10x5x5=250
5x15x5=375
250+250+375=875
Hope this helps!
What is the middle term of ( 2x-4)2
Answer:
-16x
Step-by-step explanation:
step 1
[tex](2x-4) (2x-4)[/tex]
step 2
[tex]4x^{2} - 8x - 8x +16[/tex]
step 3
[tex]4x^{2} -16x +16[/tex]
answer
-16x
GIVING OUT BRAINLIEST TO FIRST CORRECT ANSWER✅
Answer:
top right graph
Step-by-step explanation:
top right
Answer:
top right graph
Step-by-step explanation:
8x + 5y = 35 solve for y
Answer:
y = -8/5x + 7
Step-by-step explanation:
Step 1: Write equation
8x + 5y = 35
Step 2: Solve for y
Subtract 8x on both sides: 5y = 35 - 8xDivide both sides by 5: y = 7 - 8/5xRewrite: y = -8/5x + 7The graph models the heights, in feet, of two objects dropped from different heights after x seconds.
On a coordinate plane, y = f (x) curves down through (0, 35) and (1, 20). G (x) curves down through (0, 30) and (0.5, 25).
Which equation represents g(x) as a transformation of f(x)?
g(x) = f(x) – 5
g(x) = f(x – 5)
g(x) = f(x) + 5
g(x) = f(x + 5)
Answer:
g(x) = f(x) + 5
Step-by-step explanation:
C
Answer: g(x) = f(x) - 5
Step-by-step explanation:
y = mx + b
The Graph of g(x) is 5 units down from the graph of f(x)
If you bought a hamburger for $2.30 and paid for it with a 5 dollar bill, how much change would you receive?
what fraction is equivilent to 2/-6?
Answer:
2/6 is equivilent to 1/3
Step-by-step explanation:
You simplify it and then divide by the biggest number that goes into both.After,dividing you get 1/3.Your welcome.
Not sure what it is, does anyone know?
Answer:
110 degrees
Step-by-step explanation:
it is 110 degrees because on a line comebinedt is 180 degrees. And you already ahve one side which is 70 degrees. So 180 minus 70 is 110 degrees.
Answer:
m5 would be 110 degrees
Step-by-step explanation:
so basically all you have to do for that problem is subtract 70 from 180
I'll mark you as brainliest if you give me the correct answer!!!
Ayana's favorite brownie recipe calls for 1/2 of a cup of flour for every 1/3 of a cup of cocoa powder. For a bake sale, she plans to make a larger batch with 1 cup of cocoa powder. How much flour should she use?
Answer:
1 1/2 cups of flour
Step-by-step explanation:
Her original recipe calls for 1/3 cups of cocoa powder and 1/2 cups of flour. I saw we just added 2 more units to the cocoa powder! So, I decided that we should also add 2 more units to the flour and that is how I got 1 1/2 cups of flour.
(Sorry if wrong!)
Answer:
1 1/2
Step-by-step explanation:
Question 5: What is the equation of the line parallel to x = 7, passing through the point (-4, 1)?
A. X = -4
B. X = 1
C. Y = -4
D. Y = 1
Answer:
(A) x= -4
Step-by-step explanation:
The question requires you to find the equation of the line parallel to x=7
Line x=7 is a vertical line crossing the x-axis at x=7
A vertical line has undefined slope, no slope
However, parallel lines are those that do not meet and has the same slope. This means you should expect that the equation required should also have an undefined slope, slope of zero.
The line will pass through point (-4,1) and be a vertical line.
The equation of the line will be: x= -4
Can someone help me with 14 and a few others I need help ):
Answer:
26, -0.85, 17
Step-by-step explanation:
hi! so for 14, you can plug in -11 for every x in the equation.
f(-11)= 15-(-11)
=15+11
=26
your answer is 26.
for 15, we can plug in 0.3 for x.
g(0.3)=-2.5(0.3)-0.1
= -0.75-0.1
= -0.85
your answer is -0.85.
for 16, you can plug in -17 for x.
f(-17)= -(-17)
=17
your answer is 17.
Answer:
14: 26
15: -8.5
16: 17
Step-by-step explanation:
The f(x) basically gives you what x is, as the inside of parenthesis means the value of x. You then can plug in x into the equation for each of the equations. Whenever you get something like 24- (-42) The negatives cancel out and you add the two values together instead.
Hope this helps!
2 1/2 =1 2/3 ÷y
what is y
Answer: 0.664
Step-by-step explanation: 1.666/0.664=2.5
How can you describe two numbers that add to zero?
Answer:
I think it its 0 its called the additive identity because when you add it to a number, the result you get is the same number.
Step-by-step explanation:
For example, 5 + 0 = 5 Any two numbers whose sum is zero, such as 3 and -4, because 3 + (-3) = 0.
During science class,jimmy heated a substance and recorded the temperature of the substance over several minutes. He used the data to make the graph shown.
It’s -18 that’s the answer
Please help me with this problem and if you can show your work
Answer:
2.9
just answering wrong because i need points sorry
The value of investments in the stock market change daily. Suppose you buy a stock for $4,811. It increases in value by 7% and then decreases 8% and then increases again by 9%. What is the new value?