Two methods, A and B, are available for teaching Spanish. There is a 70% chance of successfully learning Spanish if method A is used, and a 85% chance of success if method B is used. However, method B is substantially more time consuming and is therefore used only 20% of the time (method A is used the other 80% of the time). The following notations are suggested:

A—Method A is used.
B—Method B is used.
L—Spanish was learned successfully. A person learned Spanish successfully.

What is the probability that he was taught by method A?

Answers

Answer 1

Answer:

0.7671 = 76.71% probability that he was taught by method A

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Person learned Spanish successfully.

Event B: Method A was used.

Probability of a person learning Spanish successfully:

70% of 80%(using method A)

85% of 20%(using method B)

So

[tex]P(A) = 0.7*0.8 + 0.85*0.2 = 0.73[/tex]

Probability of a person learning Spanish successfully and using method A:

70% of 80%, so:

[tex]P(A \cap B) = 0.7*0.8 = 0.56[/tex]

What is the probability that he was taught by method A?

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.56}{0.73} = 0.7671[/tex]

0.7671 = 76.71% probability that he was taught by method A


Related Questions

Tourism is extremely important to the economy of Florida. Hotel occupancy is an often-reported measure of visitor volume and visitor activity (Orlando Sentinel, May , ). Hotel occupancy data for February in two consecutive years are as follows. Current Year Previous Year Occupied Rooms 1,400 1,309 Total Rooms 1,750 1,700 a. Formulate the hypothesis test that can be used to determine whether there has been an increase in the proportion of rooms occupied over the one-year period. Let population proportion of rooms occupied for current year population proportion of rooms occupied for previous year - Select your answer - - Select your answer - b. What is the estimated proportion of hotel rooms occupied each year (to decimals)

Answers

Answer:

H1 : P1 - P2 = 0

H1 : P1 - P2 > 0

Step-by-step explanation:

The test to be performed on the given data is ; difference in proportion ;

P1 = proportion od rooms in current year

P2 = proportion of rooms

The null hypothesis ``, H0 : p1 - p2 (this onstage null hypothesis and it is the initial truth, representing the notion that no difference in proportion exists.

H1 : P1 - P2 = 0

The alternative hypothesis takes takes the side that there is an increase on proportion of rooms occupied :

H1 : P1 - P2 > 0

round 6.8 to nearest hundredth

Answers

Answer:

6.8

Step-by-step explanation:

The number is already rounded to the nearest tenth and hundredth.

What is the next three-term of the geometric sequence? 60, 30, 15...?

Answers

Answer:

7.5

Step-by-step explanation:

it is feometeic progression

r=0.5

in an examination 30% of the candidates failed in English and 35% failed in general studies and 27% failed in both subjects.if310 candidates passed in both how many candidates appeared in the examination​

Answers

Answer:

500

Step-by-step explanation:

A radioactive material is known to decay at a yearly rate proportional to the amount at each moment. There were 1000 grams of the material 10 years ago. There are 980 prams right now. What will be the amount of the material right after 20 years?
a. 10 ln 2/ln(1000/980)
b. 10^6/980
c. 980^3/10^6
d. 980^2/10^3

Answers

Answer:

Amount left is 941.95 g.

Step-by-step explanation:

initial amount = 1000 g

time = 10 years

amount left =  980 grams

Now

[tex]980 = 1000 e^{-\lambda t}\\\\e^{\lambda\times 10}= 1.02\\\\10 \lambda = ln 1.02\\\\\lambda = 1.98\times10^{-3} per year[/tex]

time t = 20 years

Let the amount is N.

[tex]980 = 1000 e^{-\lambda t}\\\\e^{\lambda\times 10}= 1.02\\\\10 \lambda = ln 1.02\\\\\lambda = 1.98\times10^{-3} per year\\N = 980 e^{- 1.98\times 10^{-3}\times 20}\\\\ln N = ln 980 - 0.0396\\\\ln N = 6.88 - 0.0396 = 6.86\\\\N = 941.95 g[/tex]

1. Mary got the following scores: 83, 88, 78, 80, and 90 in her examination in English. What is the mean score of Mary?
A. 83.08
B. 83.8
C. 88.38
D. 88.83

2. A list of 5 pulse rates: 70, 64, 80, 74, and 92. Which of the following is the median for this list? *
A. 80
B. 77
C. 76
D. 74

3. After checking the summative test of her 50 students, Teacher Rose found out that most of her students got 38 correct answers out of 50-item test. Which measure of central tendency do 38 represent?
A. frequency
B. median
C. mode
D. range

4. Mary found out that the difference between her highest score and lowest score in the first periodic test is 27. What measure of variability did she use?
A. range
B. mean
C. class size
D. class interval

5. What is the average deviation of the scores 5, 4, 3, 6, and 2?
A. 3.5
B. 3
C. 2.5
D. 1.2

6. If the range of the grouped data is 30 and the lower class boundary is 64.5, which of the following is the upper class boundary of the distribution?
A. 84.5
B. 85.5
C. 90.5
D. 94.5
If you have the variance, how do you get the standard deviation?
A. Square it
B. Take the square root
C. Take the reciprocal
D. Divide it by the sample size

7. If the standard deviation is 14.3, which of the following is the variance?
A. 204.49
B. 104.5
C. 28.6
D. 24.94

please answer this guys, i really need your help.​

Answers

Answer:

1=83.08

Step-by-step explanation:

mean=summation of number divided by number

what is the value of -2x²y³ when ×=2 and y=4?​

Answers

Answer:

1024

Step-by-step explanation:

Given :-

x = 2 y = 4

Value of -2x²y³

2x³ y³2 * (2)³ * (4)³2 * 8 * 64 1024

Answer:

254

Step-by-step explanation:

^ <- this is the square sign

-2x^y^3

x=2

y=4

put x values in to x place and y value in to y place.

-2(2)^2(4)^3

Find the squares and - it with 2

-2(4)(64)

2-256=254

:. the value of -2x^2y^3 =254

That the answer.

Hope this is what you asked.

i’ll give brainliest to right answer please hurry

Answers

Answer:

Scientific notation uses exponential notation. When a number is written in scientific notation, the exponent tells you if the term is a large or a small number. A positive exponent indicates a large number and a negative exponent indicates a small number that is between 0 and 1.

Answer:

Look at the exponitial factor. If it is like 10^2 or like 10^10 the number is very big because it is raised to a very big power. Oppisitely, when it is rasied to a negative number, the number producted will have many decimal places. For example 10^-1 is literaly 0.1.

Step-by-step explanation:

Yes I got u

Question 9 of 10
What is the area of the polygon given below?
3
3
19
14
2
12

Answers

Answer:

Please could you add an image, maybe I could answer then

Step-by-step explanation:

271 unit² is the  area of the polygon. The correct option is option B among all the given options.

What is area?

The size of a patch on a surface is determined by its area. Surface area is defined as the circumference of an open surface or indeed the boundaries of a three-dimensional object, whereas the area of a plane region and plane area relates to the area of a form or planar lamina.

Area can be interpreted as the quantity of material with such a specific thickness required to create a replica of the shape or as the quantity of paint required to completely cover a surface in a single coat. This is the two-dimensional equivalent of the volume of a solid or the length of a curve.

The area is the sum of 3 rectangles are:

First          12 × 19 = 228

Second       3 × 3   = 9

Third           2 × 17 = 34

total area = 228 + 34 + 9 =  271 unit²

Therefore,  271 unit² is the  area of the polygon. The correct option is option B.

To know more about area, here:

https://brainly.com/question/12187609

#SPJ7

Your question is incomplete but most probably your full question was,

What is the area of the polygon given below

HELP PLSSSSS
Solve each system with substitution

Answers

Answer:

x = -1 and y = -3

Step-by-step explanation:

1.

y = x-2 ....(1)

y = 4x+1 ....(2)

Put the values of y from equation (1) to (2).

x-2 = 4x+1

-2-1 = 4x - x

-3 = 3x

x = -1

Now put the value of x in equation (1).

y = -1-2

y = -3

So, the values of x and y are -1 and -3 respectively.

RESUELVE USANDO LAS PROPIEDADES DE LA POTENCIA
PLISSSSSSSSS CON PROCEDIMIENTOOOOOOO

Answers

Answer:

Tenemos dos propiedades de la potencia en este caso:

Para un numero real A:

[tex]A^0 = 1[/tex]

[tex](A^n)^m = A^{n*m}[/tex]

En este caso nuestra ecuación es:

[tex][ [(\frac{0.1234}{-3.2098})^4]^3]^0[/tex]

usando la segunda propiedad, podemos reescribir como:

[tex][ [(\frac{0.1234}{-3.2098})^4]^3]^0 = (\frac{0.1234}{-3.2098})^{4*3*0} = (\frac{0.1234}{-3.2098})^0[/tex]

Y acá tenemos un numero real a la potencia 0, sabemos que esto es igual a 1, entonces:

[tex](\frac{0.1234}{-3.2098})^0 = 1[/tex]

A bottle maker believes that 23% of his bottles are defective.If the bottle maker is accurate, what is the probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%? Round your answer to four decimal places.

Answers

Answer:

The appropriate answer is "0.9803".

Step-by-step explanation:

According to the question,

The probability of sample proportion differs from population proportion by les than 4% will be:

= [tex]P(-\frac{0.04}{\sqrt{\frac{0.23\times 0.77}{602} } }<z<\frac{0.04}{\sqrt{\frac{0.23\times 0.77}{602} } } )[/tex]

= [tex]P(-\frac{0.04}{\sqrt{\frac{0.1771}{602} } }<z<\frac{0.04}{\sqrt{\frac{0.1771}{602} } } )[/tex]

= [tex]P(-2.33<z<2.33)[/tex]

= [tex]0.9803[/tex]

Mr. Alvarado bought a total of 20 pounds of grass seed at the nursery for $168. He paid $9 per pound for Kentucky blue grass and $6 per pound for Tall Fescue. Which system of equations can be used to find the amount x (in pounds) of Kentucky blue grass and the amount y (in pounds) of Tall Fescue Mr. Alvarado purchased?

Answers

Answer:

K+T=20

$9K + $6T = $168

K is the Kentucky blue grass in pounds

T is the Tall fescue in pounds

Step-by-step explanation:

You can start with the first equation. We don't know the exact amounts of each but we know that there was a total of 20 pounds, and there were 2 types of grass seeds, so we can get that the amount of pounds of Kentucky blue grass(K) and the pounds of Tal Fescue(T) has a sum of 20.

K + T = 20

For the second equation we know that there is a sum of $168 so we'll start with that. Then, we know he paid $9 per pound of K so $9* the value of K is the amount paid for Kentucky blue grass total. This can be represented as 9K. We do the same for T, 6T. Since the sum of the cost of $9T and $6K must be $168 we can write this as:

$9K + $6T = $168

help me with this please pleaseee!

Answers

Answer:

2

Step-by-step explanation:

Since the two rectangles are similar, the ratio of their similar sides will be a constant k

Hence;

18/9 = 12/6 = k

Since they are all the same, then;

k = 18/9

k = 2

Hence the scale factor is 2

Answer:

D. 1/2

Step-by-step explanation:

The scale factor is the ratio of corresponding sides:

k = 9/18 = 1/2

or

k = 6/12 = 1/2

Correct choice is D

pls help me and answer it correctly:)​

Answers

Answer:

the biggest frequency is 6

and the least frequency is 4

HELP
Identify the domain of the function shown in the graph.

Answers

Answer:

D = [4, 10]

Step-by-step explanation:

Since the line starts when x = 4, the domain begins there. And since the line ends when x=10, the domain ends there.

I need help with this word problem.

Answers

Answer:

$3.22 per square feet

Step-by-step explanation:

To solve, I usually set up an equation:

sq ft  = 12 1/2 = 1

 $        40.21     x

Then, use cross multiplication.

(12 1/2)x=40.21

Divide both sides by 12 1/2 or 12.5

x = 3.2168

Round to the hundredths place [because we're dealing with money]

$3.22

I hope this helps!

Answer:

3.22 per sq ft

Step-by-step explanation:

Take the total cost and divide by the amount of tiles

40.21 / 12.5

3.2168 per sq ft

Rounding to the nearest cent

3.22 per sq ft

The cost of renting a car is $46/week plus $0.25/mile traveled during that week. An equation to represent the cost would be y = 46 + 0.25x, where x is the number of miles traveled.

what is your cost if you travel 59 miles
cost: 60.75

if your cost Is $66.00, how many miles were you charged for traveling?

miles: ?


you have a max of $100 to spend on a car rental. what would be the maximum number of miles you could Travel?

max miles: ?​

Answers

Answer:

If your cost Is $66.00, how many miles were you charged for traveling?

y = cost = $66

[tex]66=46+0.25x\\66-46=0.25x\\20=0.25x\\x=\frac{20}{0.25} =80[/tex]80 miles

You have a max of $100 to spend on a car rental. what would be the maximum number of miles you could Travel?

y = cost = $100

[tex]100=46+0.25x\\100-46=0.25x\\54=0.25x\\x=\frac{54}{0.25} =216[/tex]216 miles

AY
5
The slope of the graphed line is 2. Which formulas HELP PLEASEEEE
3
represent the line that is graphed? Check all that apply.
4
1(4,4)
3
(1/2)
Oy-1 = {(x-2)
Oy-2 = {(x - 1)
Oy-4 = (x - 4)
x
2 3 4 5
2
o flux) = { x + 1
3
47
4
f(x) = 2 x + 4
5

Answers

Answer:

y - 2 = 2/3 (x-1)

OR

y - 4 = 2/3(x-4)

NOTE ;ALL WILL GIVE THE SAME RESULT

Step-by-step explanation:

With this graph,the equation can be found on a straight line as the graph is .

So the formula is

[tex]y - y1 = m(x - x1)[/tex]

where your m is your gradient or slope as already said,the equation can be used by this formula (note;after finding your normal slope (not on a straight line ) firstly)

When you are done take any of the points connecting to the x axis and y axis directly as in (4,-4) or (2,1)

Let your first number be x1 and second y1 and place it in the formula .

NOTE: Y and x is constant and your general solution should be in the form;

y = mx +c

where m is still your normal slope.

I really don’t understand graphs

Answers

the answer would be A

(-4x+6)+(x-5) please answer I’ll be happy :)

Answers

Answer:

− 3 x + 1

Step-by-step explanation:

Answer: -3x + 1

Step-by-step explanation: I know Math O_O

A cat is running away from a dog at a speed of 3m/s. originally, the distance between them was 48 meters. What should be the speed of the dog to catch with the cat in 1 minute?

Answers

Answer:

[tex]3.8\:\mathrm{m/s}[/tex]

Step-by-step explanation:

Use the formula [tex]d=rt[/tex] (distance is equal to rate/speed multiplied by time) to solve this problem.

We know that one minute is equal to 60 seconds. Therefore, the distance travelled by the cat in 1 minute is equal to [tex]d=3\cdot 60=180\text{ meters}[/tex].

To catch the cat, the dog needs to also cover an additional 48 meters, because the cat was initially 48 meters away from the dog and it ran away from the dog. Hence, the dog will need to cover [tex]180+48=228[/tex] meters in one minute.

Therefore, we have:

[tex]228=60r,\\r=\frac{228}{60}=\boxed{3.8\:\mathrm{m/s}}[/tex]

Answer:

[tex] \boxed{3.8 \: m/s} [/tex]

Explanation

The first step is to set the speed and the distance equal to the unknown rate of the dog.

3 m/s + 48 m = x m/60s.

Then substitute 60s in for both rates to get distance.

180m + 48m = x m/60

228m = 60x m

÷60 ÷60

3.8m = x m/s.

x = 3.8m/s

Last softball season, Pamela had 46 hits, a combination of singles (1 base), doubles (2 bases), and triples (3 bases). These 46 hits totaled 66 bases, and she had 4 times as many singles as doubles. How many doubles did she have?

Answers

Answer:

She had 8 doubles.

Step-by-step explanation:

This question is solved by a system of equations.

I am going to say that:

x is the number of singles.

y is the number of doubles

z is the number of triples.

46 hits

This means that [tex]x + y + z = 46[/tex]

46 hits totaled 66 bases

This means that:

[tex]x + 2y + 3z = 66[/tex]

4 times as many singles as doubles

This means that [tex]x = 4y[/tex]

So

[tex]x + 2y + 3z = 66[/tex]

[tex]4y + 2y + 3z = 66[/tex]

[tex]6y + 3z = 66[/tex]

And

[tex]x + y + z = 46[/tex]

[tex]4y + y + z = 46[/tex]

[tex]5y + z = 46 \rightarrow z = 46 - 5y[/tex]

Then

[tex]6y + 3z = 66[/tex]

[tex]6y + 3(46 - 5y) = 66[/tex]

[tex]6y + 138 - 15y = 66[/tex]

[tex]9y = 72[/tex]

[tex]y = \frac{72}{9}[/tex]

[tex]y = 8[/tex]

She had 8 doubles.

PLS HELP QUICK I WILL GIVE YOU BRAINLIEST:

Given that angle abc=70° and angle bcd=110°. Is it possible (consider all cases): That line AB intersects line CD?

Answers

Answer:

Given that angle abc = 70° and angle bcd = 110°. Is it possible (consider all cases): That line AB intersects line CD?

yes.

Step-by-step explanation:

#CarryOnLearning

Suppose f(x,y,z) = x2 + y2 + z2 and W is the solid cylinder with height 7 and base radius 2 that is centered about the z-axis with its base at z = −2. Enter θ as theta.

A) As an iterated integral, ∭WfdV = ∫BA∫DC∫FE dzdrdθ with limits of integration.

B) Evaluate the integral.

Answers

In cylindrical coordinates, W is the set of points

W = {(r, θ, z) : 0 ≤ r ≤ 2 and 0 ≤ θ ≤ 2π and -2 ≤ z ≤ 5}

(A) Then the integral of f(x, y, z) over W is

[tex]\displaystyle\iiint_W(x^2+y^2+z^2)\,\mathrm dV = \int_0^{2\pi}\int_0^2\int_{-2}^5r(r^2+z^2)\,\mathrm dz\,\mathrm dr\,\mathrm d\theta[/tex]

(B)

[tex]\displaystyle \int_0^{2\pi}\int_0^2\int_{-2}^5r(r^2+z^2)\,\mathrm dz\,\mathrm dr\,\mathrm d\theta = 2\pi \int_0^2\int_{-2}^5(r^3+rz^2)\,\mathrm dz\,\mathrm dr \\\\\\= 2\pi \int_0^2\left(zr^3+\frac13rz^3\right)\bigg|_{z=-2}^{z=5}\,\mathrm dr \\\\\\= 2\pi \int_0^2\left(\frac{133}3r+7r^3\right)\,\mathrm dr \\\\\\= 2\pi \left(\frac{133}6r^2+\frac74r^4\right)\bigg|_{r=0}^{r=2} \\\\\\= 2\pi \left(\frac{110}3\right) = \boxed{\frac{220\pi}3}[/tex]

SOMEONE HELP PLEASE! So for this problem the answer I got is $4000. Is that the correct or incorrect answer? Can someone please help me if it is the incorrect answer. Thank you for your time.

Answers

Answer:

You're correct

Step-by-step explanation:

Gil wants to have $9,500 in 7 years. Use the present value formula to calculate how much he should invest now at 2% interest, compounded semiannually in order to reach his goal.

Answers

Answer:

9500 × 1.02^7

Step-by-step explanation:

9500 × 1.02^7

Calculate that

Question 1 of 10
Estimate the difference of the decimals below by rounding to the nearest
whole number. Enter your answer in the space provided.
46.327
-4.801

Answers

Answer:

Step-by-step explanation:

46.327=46 ( neaarest whole number)

-4.801=-5 (nearest whole number)

46-(-5)=46+5=51

Question 9 of 44 What is the measure of 0 ?
A. 2.5. radians
B. 4 radians
C. 5 radians
D. 2.5 Π radians ​

Answers

Answer:

the answer to your question is B. 4 radians

A race is 3 miles long. There are water stations every 3/4 mile along the route. How many water stations are along the route?

Answers

There will be 4 water stations.

Why?

3/4 = .75 as a decimal

Personally, I believe that it’s easier to use decimals, I can explain the way in fractions in the comments if you’d like, just ask.

Anyway, .75 • 4= 3

or 3 / .75 = 4 (division is easier with bigger numbers)

so, there will be 4 water stations, given that the one race is 3 miles long.

If this explanation seems unclear, I’d be happy to explain. Feel free to ask in the comments!! I’m happy to help.

Hope this helps!

(If you find this answer helpful, please consider marking me brainliest, Thanks!)
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