Suppose that 20° of boys opted for mathematics and 40% of girls opted for mathematics. What is the probability that a student opted for mathematics if half of the class is girls?​

Answers

Answer 1

Answer: 30%

Step-by-step explanation:

Let A be the probability of a student opting for mathematics - it consists of either boy opting for mathematics or girl opting for mathematics. As there is "or" we need to sum these probabilities.

[tex]P(A) = P(B)* P(M|G) + P(G)*P(M|G)[/tex]

[tex]P(A) = \frac{1}{2} * \frac{20}{100} + \frac{1}{2} * \frac{40}{100}[/tex]

[tex]P(A) = 3/10 = 0.3[/tex]

=> 30%

Answer 2

Answer:

30% Chance

Step-by-step explanation:

This one is rather simple. If half the class is girls, split 40 into half. Do the same with 20 if half is boys. Add 10 and 20 and you get 30.


Related Questions

4
On a plan with a scale of 1:50, the floor of a rectangular cupboard is
shown with dimensions 25 cm by 3.6 cm. What are the actual dimensions
of the floor? Give your answers in metres.



Anyone know the answer ?

Answers

Answer:

The actual dimensions of the floor are 12,5m by 1,8m.

Step-by-step explanation:

Scale problems are solved by proportions, using a rule of three.

Scale of 1:50

This means that each cm on the cupboard has a real dimension of 50 cm

25 cm on the cupboard:

So the real dimension is:

25*50 = 1250 cm = 12,5m

3.6 cm

The real dimension is:

3.6*50 = 160 cm = 1,8 m

The actual dimensions of the floor are 12,5m by 1,8m.

Help please somebody ASAP

Answers

Answer:

[tex]\frac{-2x+11}{(x-4)(x+1)}[/tex]

Step-by-step explanation:

I don't think we can factor this so we'll have to multiply to make the denominators the same

[tex]\frac{3(x+1)}{(x^2-3x-4)(x+1)}-\frac{2(x^2-3x-4)}{(x+1)(x^2-3x-4)}\\\\\frac{3x+3-(2x^2-6x-8)}{(x^2-3x-4)(x+1)}=\frac{-2x^2+9x+11}{(x^2-3x-4)(x+1)}\\-2x^2+9x+11=(x+1)(-2x+11)\\\\x^2-3x-4=(x+1)(x-4)\\\frac{(x+1)(-2x+11)}{(x+1)(x-4)(x+1)}=\frac{-2x+11}{(x-4)(x+1)}[/tex]

can anyone help me and explain

Answers

Answer:

cf

=41

5 f-46

Step-by-step explanation:

thiis is the answer

Answer:

To find the inverse, switch the y(F(C)) and the x(C) variables.

So this function:

[tex]y=\frac{9}{5}x+32 \\[/tex]

Will become this function:

[tex]x=\frac{9}{5}y+32 \\[/tex]

You will then solve for y:

[tex]x=\frac{9}{5}y+32 \\x-32=\frac{9}{5}y\\5(x-32)=5(\frac{9}{5}y)\\5x-160=9y\\y=\frac{5x-160}{9}\\y=\frac{5x}{9}-\frac{160}{9}[/tex]

Substitute in the variables of this problem:

[tex]C(F)=\frac{5C}{9}-\frac{160}{9}[/tex]

Exactly how many planes contain points J, K, and N?
a - 0
b - 1
c - 2
d - 3

Answers

A- 0 ..... one plane contains k and n but there isn’t a plane that contains all three points

for the equation (x+3)(x+1)=1 explain why the solutions are not -3 and -1

Answers

Answer:

Step-by-step explanation:

(x+3)(x+1)=1

x²+3x+x+3=1

x²+4x+2=0

x²+4x+4=-2+4

(x+2)²=2

x+2=±√2

x=2+√2

and x=2-√2

so x≠-3

and x≠-1

Write the geometric sequence in function notation.
4,2,1,1/2,1/4,...
A) AX) = (2) - (1/4)x - 1
OB) Ax) = (2) - (1/2)x - 1
C) Ax) = (4) · (/4)x - 1
D AX) = (4) · (1/2)x - 1

Answers

Answer:

D

Step-by-step explanation:

Please help ASAP !!! Thank you !

Answers

(1) =(a+b)(3c-d) =a(3c-d)+b(3c-d) =3ac-ad+3bc-bd

(2) =(a-b)(c+2d) =a(c+2d)-b(c+2d) =ac+2ad-bc-2bd

(3) =(a-b)(c-2d) =a(c-2d)-b(c-2d) =ac-2ad-bc+2bd

(4) =(2a+b)(c-3d) =2a(c-3d)+b(c-3d) =2ac-6ad+bc-3bd

A small radio transmitter broadcasts in a 69 mile radius. If you drive along a straight line from a city 93 miles north of the transmitter to a second city 78 miles east of the transmitter, during how much of the drive will you pick up a signal from the transmitter?

Answers

Answer:

See Explanation

Step-by-step explanation:

According to the Question,

We have A small radio transmitter that broadcasts in a 69-mile radius. If you drive along a straight line from a city 93 miles north of the transmitter to a second city 78 miles east of the transmitter.

Thus,

The distance that you get reception is the length of the chord created by the intersection of the circle defining the edge of transmission and the line defining the car trip.

 x2 + y2 = 69²               this is the circle

And,

The Transmitter at the origin

City to the north at (0,93)  & City to the east at (78,0)  

the Slope is M=(-93/78)

Intercept is B= y - mx ⇒  93 - (-93/78)(0) = 93

The equation of the line between the cities is y = (-93/78)x + 93

y = -93x/78 + 93           this is the line

Now, Solve the above two Equations

The intersection is gotten from the picture or solving:

x^2 + [(-93/78)*x + 93]^2 = 69^2

on solving we get, the points approximately are: (67.952,11.98 ) and (23.6277, 64.82)

Now,

From the Pythagorean theorem the total distance of the trip is:  

d1 = √(93^2 + 78^2) ≈ 121.37miles  

And the distance when the signal is picked up is:

d2 =√ [(67.952-23.627)^2 + (64.82 - 11.98)^2] ≈ 68.96 miles

You will pick up a signal from the transmitter in (d2/d1)*100 = 56% of the drive.

In what country of United states of heightlandia, the height measurements of ten year old children are approximately normally distributed with a mean of 53.2 inches and standard deviation of 6.7 inches?

Answers

Step-by-step explanation:

hi I can help you out in this work via Wazapp

The salaries of 235 nurses were recorded and analyzed. The analyst later found that the highest salary was incorrectly recorded as 10 times the actual amount. After the error was corrected, the report showed that the corrected value was still higher than any other salary. Which sample statistic must have changed after the correction was made?

Answers

The sample statistic that must have changed after the correction was made is mean. Because mean is based on all the observation in the data. So changing any value in the data will impact mean.

Changing the highest salary in the data will have no impact on median because median lies at the center of data.

Changing the highest salary in the data will have no impact on mode because mode is the most frequently occurring value in the data.

Changing the highest salary in the data will have no impact on minimum because minimum is the smallest value in the data.

Hence the only statistic which will change is mean.

Answer: A-Mean

Step-by-step explanation:

A.) Mean

B.) Median

C.)  Mode

D.)  Minimum

The population of watesville decreases at a rate of 1.6% each year if the population was 62,500 in 2015 what will it be in 2021

Answers

Answer:

Step-by-step explanation:

We need to first find the model for this particular situation, knowing that this is an exponential decay problem. The main equation for exponential growth/decay (as far as population goes for our problem) is

[tex]y=a(b)^x[/tex] where a is the initial population, b is the rate of decrease in the population which can also be written as (1 - r), y is the population after a certain amount of time, x, goes by. We will let year 2015 = 0 so year 2021 can = 6. This keeps our numbers lower and doesn't change the answer!

Our initial population in the year x = 0 is 62500. Our rate of decay is

(1 - .016) so our b value is .984

Filling in to find our model:

[tex]y=62500(.984)^x[/tex]

Now we can use that model and sub in a 6 for x to find the population in the year 2021:

[tex]y=62500(.984)^6[/tex] and

y = 62500(.9077590568) so

y = 56734.9 or, rounded to the nearest person, 56735

Help 20 pointss nowww it is math and pls I need it

Answers

Answer:

The answer is b

Step-by-step explanation:

Step-by-step explanation:

hope it helps you..........

Complete the information for that object by making estimates using appropriate units of measurement of the dimensions and by getting the actual measurements using an appropriate measuring instrument. ​

Answers

Answer:

hlo how are u?whats ur day is going

In the diagram, WZ=StartRoot 26 EndRoot.

On a coordinate plane, parallelogram W X Y Z is shown. Point W is at (negative 2, 4), point X is at (2, 4), point Y is at (1, negative 1), and point Z is at (negative 3, negative 1).

What is the perimeter of parallelogram WXYZ?

units
units
units
units

Answers

Answer:

[tex]P = 8 + 2\sqrt{26}[/tex]

Step-by-step explanation:

Given

[tex]W = (-2, 4)[/tex]

[tex]X = (2, 4)[/tex]

[tex]Y = (1, -1)[/tex]

[tex]Z = (-3,-1)[/tex]

Required

The perimeter

First, calculate the distance between each point using:

[tex]d = \sqrt{(x_1 - x_2)^2 + (y_1 -y_2)^2[/tex]

So, we have:

[tex]WX = \sqrt{(-2- 2)^2 + (4-4)^2 } =4[/tex]

[tex]XY = \sqrt{(2- 1)^2 + (4--1)^2 } =\sqrt{26}[/tex]

[tex]YZ = \sqrt{(1- -3)^2 + (-1--1)^2 } =4[/tex]

[tex]ZW = \sqrt{(-3--2)^2 + (-1-4)^2 } =\sqrt{26}[/tex]

So, the perimeter (P) is:

[tex]P = 4 + \sqrt{26} + 4 + \sqrt{26}[/tex]

[tex]P = 8 + 2\sqrt{26}[/tex]

Answer:

its D.

Step-by-step explanation:

took test

J. Aitchison collected expenditures data for 20 randomly selected single men and 20 randomly selected single women. He uses the data to conduct a hypothesis test to determine if the mean percent of expenditures that goes toward housing (including fuel and light) is different for men and women. What is the correct alternative hypothesis?
a. Md = 0
b. μα = 0
c. ud > 0
d. Opmen — Вwomen
e. Himen > Mwomen
f. Mmen Mwomen

Answers

Answer:

The alternative hypothesis is [tex]H_1: \mu_M - \mu_W \neq 0[/tex], considering M for men and W for women.

Step-by-step explanation:

He uses the data to conduct a hypothesis test to determine if the mean percent of expenditures that goes toward housing (including fuel and light) is different for men and women.

At the null hypothesis, we test if there is not difference, that is, the difference of the mean is 0, so:

[tex]H_0: \mu_M - \mu_W = 0[/tex]

At the alternative hypothesis, we test if there is a difference, that is, the difference of the means is different of 0, so:

[tex]H_1: \mu_M - \mu_W \neq 0[/tex]

Four times a number is 88 less than 6 times the number. Find the number.​

Answers

Answer:

44

Step-by-step explanation:

Let x represent the number.

Create an equation, and solve for x:

4x = 6x - 88

-2x = -88

x = 44

So, the number is 44.

The number is 44.

To find the number.

What is arithmetic?

science that deals with the addition, subtraction, multiplication, and division of numbers and properties and manipulation of numbers. Arithmetic is the basics of the abstract science of numbers and operations on them. The formula for any arithmetic sequence is this: an = a1 + d (n - 1).

Given that:

Let x represent the number.

Create an equation, and solve for x:

4x = 6x - 88

-2x = -88

x = 44

So, the number is 44.

Learn more about arithmetic here:

https://brainly.com/question/24163536

#SPJ2

Jill has 32 crayons. She loses 4 of the crayons. How many are left?

Answers

Answer:

the answer here is d

the answer is d

Answer:

28

Step-by-step explanation:

Total number of crayons = 32

Number of crayons lost = 4

Therefore, number of crayons she is left with is : 32 - 4 = 28

Working :  

    [tex]32\\04 - \\\overline{28}[/tex]

The following data was collected to explore how the average number of hours a student studies per night and the student's GPA affect their ACT score. The dependent variable is the ACT score, the first independent variable (x1)is the number of hours spent studying, and the second independent variable (x2) is the student's GPA
Effects on ACT Scores
Study Hours GPA ACT Score
5 4 27
5 2 18
5 3 18
1 3 20
2 4 21
Step 1 of 2: Find the p-value for the regression equation that fits the given data. Round your answer to four decimal places.
Step 2 of 2: Determine if a statistically significant linear relationship exists between the independent and dependent variables at the 0.01 level of significance. If the relationship is statistically significant, identify the multiple regression equation that best fits the data, rounding the answers to three decimal places. Otherwise, indicate that there is not enough evidence to show that the relationship is statistically significant.

Answers

Answer:

Pvalue = 0.1505

y = 0.550x1 + 3.600x2 + 7.300

Step-by-step explanation:

Given the data :

Study Hours GPA ACT Score

5 4 27

5 2 18

5 3 18

1 3 20

2 4 21

Using technology, the Pvalue obtained using the Fratio :

F = MSregression / MSresidual = 30.228571/ 8.190476 = 3.69

The Pvalue for the regression equation is:

Using the Pvalue from Fratio calculator :

F(1, 3), 3.69 = 0.1505

Using the Pvalue approach :

At α = 0.01

Pvalue > α ; Hence, we fail to reject H0 and conclude that ; There is not enough evidence to show that the relationship is statistically significant.

The regression equation :

y = A1x1 + A2x2 +... AnXn

y = 0.550x1 + 3.600x2 + 7.300

x1 and x2 are the predictor variables ;

y = predicted variable

Is a linear model or a quadratic model a better fit? Quadratic model graph quadratic model linear model

Answers

Linear model is a better fit due to my evidence of doing this answer

Round 0.485 to the nearest hundredth

Answers

Decimals start at tenths, then hundredths, then thousandths, and so on. When we round, we look at the place value that is one smaller than the one we want to round to.

So, let's take a look at the thousandths place in 0.485. The value in the thousandths place is 5. When rounding, if the value is 5 or over we round up and if the value is 4 or lower we round down. Since the value in the thousandths place is 5, we will round the hundredths place up one.

0.485 rounded to the nearest hundredth is 0.49

Hope this helps!

Answer:

0.49

Step-by-step explanation:

[tex]0<x<5=[/tex] Round down

[tex]x\geq5=[/tex] Round up

In this case, it's a round up, so the answer would be...

0.49

Hope this helped! Please mark brainliest!

What are the lower, middle, and upper quartiles of this data?
122, 164, 71, 98, 84, 147, 114, 111, 98, 85, 104, 71, 77

Answers

Answer:

71, 71, 75, 85, 98, 98, 104, 111, 114, 122, 164

The middle quartile is 98.

The lower quartile is 80

The upper quartile is 112.5

A Roper survey reported that 65 out of 500 women ages 18-29 said that they had the most say when purchasing a computer; a sample of 700 men (unrelated to the women) ages 18-29 found that 133 men said that they had the most say when purchasing a computer. What is the 99% confidence interval for the difference of the two proportions

Answers

Answer:

[tex]Z=-2.87[/tex]

Step-by-step explanation:

From the question we are told that:

Probability on women

[tex]P(W)=65 / 500[/tex]

[tex]P(W) = 0.13[/tex]

Probability on women

[tex]P(M)=133 / 700[/tex]

[tex]P(M) = 0.19[/tex]

Confidence Interval [tex]CI=99\%[/tex]

Generally the equation for momentum is mathematically given by

[tex]Z = \frac{( P(W) - P(M) )}{\sqrt{(\frac{ \sigma_1 * \sigma_2 }{(1/n1 + 1/n2)}}})[/tex]

Where

[tex]\sigma_1=(x_1+x_2)(n_1+n_2)[/tex]

[tex]\sigma_1=\frac{( 65 + 133 )}{ ( 500 + 700 )}[/tex]

[tex]\sigma_1=0.165[/tex]

And

[tex]\sigma_2=1 - \sigma = 0.835[/tex]

Therefore

[tex]Z = \frac{( 0.13 - 0.19)}{\sqrt{\frac{( 0.165 * 0.835}{ (500 + 700) )}}}[/tex]

[tex]Z=-2.87[/tex]

The strength of one's immune system can be evaluated in several ways. One of the most popular methods involves measuring the concentration of adenosine triphosphate (ATP) in the blood. In women, the mean blood ATP level is 390 ng/mL, and the standard deviation is 115 ng/mL. It has been hypothesized that women with Major Depressive Disorder (MDD) have decreased immune function. A recent study found that a random sample of 30 women with MDD had an average blood ATP level of 355 ng/mL. Using a one-sample z test, what is the p-value of this result? (HINT: This involves a one-tailed hypothesis test).

Answers

Answer:

Hence the value of p is 0.04746.

Step-by-step explanation:

The test statistic is

[tex]Z=(\bar x-\mu)/(s/vn)\\\\=(355-390)/(115/ \sqrt(30))\\\\=-1.667[/tex]

The p-value= P(Z<-1.67) =0.04746. (from standard distribution table)

Therefore p-value =0.04746.

Say you buy halibut at $19 per pound . One portion of seared halibut requires 6 ounces of halibut . How much does the halibut for one portion cost ? Round to the nearest cent .

Answers

Answer:

$7.13

Step-by-step explanation:

Given data

Cost of halibut per pound= $19

Let us convert pound to ounces first

1 pound = 16 ounces

Hence 16 ounces will cost $19

           6 ounces will cost x

cross multiply we have

x= 19*6/16

x=114/16

x=$7.13

Hence 6 ounces will cost $7.13

Carlos has an aquarium which is 45 cm long, 32 cm wide, and 35 cm high. How much water can the aquarium hold?

Answers

Answer:

volume =l×b×h

45cm×32cm×35cm=48,960cm³

45 x 32 x 35 = 50 400 cm^3 = 50.4 litres

A courier service company wishes to estimate the proportion of people in various states that will use its services. Suppose the true proportion is 0.06. If 235 are sampled, what is the probability that the sample proportion will differ from the population proportion by greater than 0.04

Answers

Answer:

0.0098 = 0.98% probability that the sample proportion will differ from the population proportion by greater than 0.04

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Suppose the true proportion is 0.06.

This means that [tex]p = 0.06[/tex]

235 are sampled

This means that [tex]n = 235[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.06[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.06*0.94}{235}} = 0.0155[/tex]

What is the probability that the sample proportion will differ from the population proportion by greater than 0.04?

Proportion below 0.06 - 0.04 = 0.02 or above 0.06 + 0.04 = 0.1. Since the normal distribution is symmetric, these probabilities are equal, which means that we can find one of them and multiply by 2.

Probability the proportion is below 0.02.

p-value of Z when X = 0.02. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.02 - 0.06}{0.0155}[/tex]

[tex]Z = -2.58[/tex]

[tex]Z = -2.58[/tex] has a p-value of 0.0049.

2*0.0049 = 0.0098

0.0098 = 0.98% probability that the sample proportion will differ from the population proportion by greater than 0.04

The level of significance is the a. same as the p-value. b. maximum allowable probability of Type I error. c. same as the confidence coefficient. d. maximum allowable probability of Type II error.

Answers

Answer:

The level of significance is the

b. maximum allowable probability of Type I error.

Step-by-step explanation:

The significance level provides the maximum probability of rejecting the null hypothesis when it is true.  It is the same as a type I error (also known as false-positive).  This error occurs when a researcher or investigator rejects a true null hypothesis that is supposed to be accepted.  It is the opposite of a type II error (false-negative), which occurs when the researcher fails to reject a false null hypothesis.

∠A and \angle B∠B are vertical angles. If m\angle A=(5x-9)^{\circ}∠A=(5x−9) ∘ and m\angle B=(8x-30)^{\circ}∠B=(8x−30) ∘ , then find the value of x

Answers

9514 1404 393

Answer:

  x = 7

Step-by-step explanation:

Vertical angles have the same measure, so ...

  m∠A = m∠B

  (5x -9)° = (8x -30)°

  21 = 3x . . . . . . . . . divide by °, add 30-5x

  7 = x . . . . . . . . . . divide by 3

A cyclist completes a journey of 500 m in 22 seconds, part of the way at 10 m/s and the remainder at 50 m/s. How far does she travel at each speed. solve by forming simultaneous equation

Answers

Answer:

150 m at 10 m/s

350 m at 50 m/s

Step-by-step explanation:

x + y = 500

x/10 + y/50 = 22

~~~~~~~~~~~~~~~~~

x + y = 500

5x  + y  = 1100

~~~~~~~~~~~~~~~~

x + y = 500

-5x  - y  = -1100

-4x = -600

x = 150

y = 350

Pls could someone help me with this​

Answers

Answer:

- Bar Gaps should be the same

Y-axis up in units of 5 would help out

Step-by-step explanation:

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