The following two way table describes students after school activities find the probability that a randomly selected student is in sports
Answers
Answer:
0.65
Step-by-step explanation:
There’s 65 students total in sports, so you divide that by 100 to get your answer
Answer:
0.65Step-by-step explanation:
sophomore + junior + senior = total number of students that play sports
20 + 20 + 25 = 65
65 ÷ 100 = 0.65
0.65 rounded to the nearest hundred would still be 0.65
Related Questions
PLEASEEEEEEE HELP!!!!!
Answers
Answer:
22.18
Step-by-step explanation:
c squared = a squared + b squared - 2ab cos c
or a instead of c in this case.
144+225-360(-0.342)
square root 492.12
Many elementary school students in a school district currently have ear infections. A random sample of children in two different schools found that 16 of 40 at one school and 13 of 30 at the other had this infection. Conduct a test to answer if there is sufficient evidence to conclude that a difference exists between the proportion of students who have ear infections at one school and the other. Find the test statistic. [Suggestion: try to use a TI 83 or a similar calculator.]
Answers
Answer:
The test statistic is [tex]z = -0.28[/tex]
Step-by-step explanation:
First, before finding the test statistic, we need to understand the central limit theorem and difference between normal variables.
Central Limit Theorem
The Central Limit Theorem estabilishes 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]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
A random sample of children in two different schools found that 16 of 40 at one school
This means that:
[tex]p_1 = \frac{16}{40} = 0.4, s_1 = \sqrt{\frac{0.4*0.6}{40}} = 0.0775[/tex]
13 of 30 at the other had this infection.
This means that:
[tex]p_2 = \frac{13}{30} = 0.4333, s_2 = \sqrt{\frac{0.4333*0.5667}{30}} = 0.0905[/tex]
Conduct a test to answer if there is sufficient evidence to conclude that a difference exists between the proportion of students who have ear infections at one school and the other.
At the null hypothesis, we test if there is no difference, that is:
[tex]H_0: p_1 - p_2 = 0[/tex]
And at the alternate hypothesis, we test if there is difference, that is:
[tex]H_a: p_1 - p_2 \neq 0[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis and s is the standard error
0 is tested at the null hypothesis:
This means that [tex]\mu = 0[/tex]
From the two samples:
[tex]p = p_1 - p_2 = 0.4 - 0.4333 = -0.0333[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.0775^2+0.0905^2} = 0.1191[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{s}[/tex]
[tex]z = \frac{-0.0333 - 0}{0.1191}[/tex]
[tex]z = -0.28[/tex]
The test statistic is [tex]z = -0.28[/tex]
Determine the volume of a sphere with a radius of 1.28 inches. Round your answer to the nearest hundredth. Use 3.14 for pi.
a.
8.78 cu. in
c.
9.78 cu. in
b.
7.48 cu. in
d.
2.48 cu. in
Answers
Answer:
A
Step-by-step explanation:
The equation is V=4/3 times Pi times radius^3
6. A stoplight at an intersection stays red for 60 second, changes to green for 45
seconds, and then turns yellow for 15 seconds. If Jamal arrives at the
intersection at a random time, what is the probability that he will have to wait at
a red light for more than 15 seconds?
Answers
Answer:
0.75 = 75% probability that he will have to wait at a red light for more than 15 seconds
Step-by-step explanation:
At each second, the stoplight is equally likely to change, which means that we use the uniform probability distribution to solve this question.
Uniform probability distribution:
Has two bounds, a and b. The probability of finding a value higher than x is given by:
[tex]P(X > x) = \frac{b - x}{b - a}[/tex]
Red for 60 seconds
So when Jamal arrives it can change in any number of seconds between 0 and 60, that is, [tex]a = 0, b = 60[/tex]
Probability that he will have to wait at a red light for more than 15 seconds?
[tex]P(X > 15) = \frac{60 - 15}{60 - 0} = \frac{45}{60} = \frac{3}{4} = 0.75[/tex]
0.75 = 75% probability that he will have to wait at a red light for more than 15 seconds
how many hundreds are in 200 + 10 + 6
Answers
Answer:
1
Step-by-step explanation:
Answer:
2?
Step-by-step explanation:
Can someone help me fast please?!
Answers
Answer:e
Step-by-step explanation:
-(5/3)=-5/3
A bus has 10 seats that can hold 2 passengers and another seat that can hold 3 passengers how many passengers can be seated on the bus
Answers
Answer:it can hold 23 passangers
Step-by-step explanation:
mclaire155 THIS IS FOR YOU not and thank you
Answers
Answer:
shhdhd
Step-by-step explanation:
Oh wow great marks
y=19
a=6
t=4
B=y+at
Can someone please help me solve this
Answers
Answer:
B= 43
Step-by-step explanation:
B=19+(6)(4)
B=19+24
B=43
Can someone answer me I don’t get it
Answers
Answer:
B, C and F
Step-by-step explanation:
Negative numbers go farther and father to the left on a number line the higher in value they get.
please help me!! asap!!
Answers
Answer:
answer: 85
Step-by-step explanation:
These add up to 360 and
85 + 85 + 95 + 95 = 360 so 85 is the answer.
Hope that helps!
A 400 gallon tank initially contains 300 gallons of water containing 0.8 lb of salt. Suppose water containing 0.6 lb of salt per gallon flows into the top of the tank at a rate of 2 gallons per minute. The water in the tank is kept well-mixed, and 7 gallons per minute are removed from the bottom of the tank. a. Write an initial value problem for S(t), the amount of salt in the tank at time t. Do not solve the equation!! b. Write an expression in terms of S for the amount of salt in the tank when the tank is one-quarter full. Show all your work on the paper you scan and submit. You do not need to type anything in the box below.
Answers
Answer:
a. dS(t)/dt + [7S(t)/(300 - 5t)] = 1.2 with S(0) = 0.8
b. S(t) = [tex]\frac{120e^{\frac{7t}{100} } }{7}[/tex] - 16.34[tex]e^{-\frac{7t}{100}[/tex]
Step-by-step explanation:
a. Write an initial value problem for S(t), the amount of salt in the tank at time t. Do not solve the equation!!
The net mass flow rate of salt dS(t)/dt = mass flow in - mass flow out
mass flow in = concentration of flow in × flow rate in = 0.6 lb/gal × 2 gal/min = 1.2 lb/min
Let S(t) be the mass of salt in the tank at time, t. The concentration of salt in the tank at time, t, C(t) = S(t)/volume of tank at time t ,V
V = V₀ + (r - r')t where V₀ = initial volume of water in tank = 300 gal, r = volume flow rate in = 2 gal/min, r'= volume flow rate out = 7 gal/min and t = time
So, V = V₀ + (r - r')t
V = 300 + (2 - 7)t
V = 300 - 5t
So, C(t) = S(t)/V = S(t)/(300 - 5t) lb/gal
Now, mass flow rate out = concentration in tank × volume flow rate out = S(t)/(300 - 5t) lb/gal × 7 gal/min = 7S(t)/(300 - 5t) lb/min
So, dS(t)/dt = mass flow in - mass flow out
dS(t)/dt = 1.2 lb/min - 7S(t)/(300 - 5t) lb
dS(t)/dt = 1.2 - 7S(t)/(300 - 5t)
So, our differential equation is
dS(t)/dt + [7S(t)/(300 - 5t)] = 1.2 with S(0) = 0.8 since we initially have 0.8 lb of salt
b. Write an expression in terms of S for the amount of salt in the tank when the tank is one-quarter full.
When the tank is one-quarter full, V = volume of tank/4 = 400 gallons/4 = 100 gallons
We now solve our differential equation
dS(t)/dt + 7S(t)/100 = 1.2
Using the integrating factor method, I.F = [tex]e^{\int\limits{\frac{7}{100} \, dt } =[/tex] [tex]e^{\frac{7t}{100} }[/tex]
[tex]e^{\frac{7t}{100}[/tex]dS(t)/dt +
d[[tex]e^{\frac{7t}{100}[/tex]S(t)]/dt = 1.2
d[[tex]e^{\frac{7t}{100}[/tex]S(t)] = [1.2
integrating both sides, we have
∫d[[tex]e^{\frac{7t}{100}[/tex]S(t)] = ∫[1.2
Let u = 7t/100. So, du/dt = 7/100 and dt = 100du/7
∫[1.2[tex]e^{\frac{7t}{100}[/tex]]dt = ∫[1.2 × 100[tex]e^{u}[/tex]]du/7 = (120/7)∫
[tex]e^{\frac{7t}{100}[/tex]S(t) = [tex]\frac{120e^{\frac{7t}{100} } }{7}[/tex] + C
S(t) = [tex]\frac{120e^{\frac{7t}{100} } }{7}[/tex] ÷ [tex]e^{\frac{7t}{100}[/tex] + [tex]e^{-\frac{7t}{100}[/tex]
S(t) = [tex]\frac{120e^{\frac{7t}{100} } }{7}[/tex] + C[tex]e^{-\frac{7t}{100}[/tex]
From our initial condition, S(0) = 0.8. So,
S(0) = [tex]\frac{120e^{\frac{7(0)}{100} } }{7}[/tex] + C[tex]e^{-\frac{7(0)}{100}[/tex]
S(0) = [tex]\frac{120e^{\frac{0}{100} } }{7}[/tex] + C[tex]e^{-\frac{0}{100}[/tex]
S(0) = [tex]\frac{120e^{0}}{7}[/tex] + C[tex]e^{0}[/tex]
0.8 = [tex]\frac{120}{7}[/tex] + C
C = 0.8 - 120/7
C = 0.8 - 17.14
C = - 16.34
So,
S(t) = [tex]\frac{120e^{\frac{7t}{100} } }{7}[/tex] - 16.34[tex]e^{-\frac{7t}{100}[/tex]
Connie mason has a coupon for 25 percent off the purchase of a necklace that has a regular price of 100 what is the price after the coupon is used
Answers
A realtor collects the data set given in DS 12.2.4 concerning the sizes of a random selection of newly constructed houses in a certain area together with their appraised values for tax purposes.
1. Fit a linear regression model with appraised value as the explanatory variable and size as the dependent variable.
2. What is the estimate of the error variance?
Answers
Answer:
12.327X + 452.084
45206.327
Step-by-step explanation:
The linear regression model obtained by fitting the data using technology is :
ŷ = 12.327X + 452.084
Where, 12.327 = slope ; 452.084 = Intercept ; X = appraised value ; y = Area
The estimated error variance which is the degree of variation between the actual and predicted value.
Error variance = ΣSSE /n-2
n = sample size = 15
ΣSSE = 587682.2638
Error variance = 587682.2638/13
Error variance = 45206.327
Why should you write everything down instead of doing the math in your head?
Answers
Answer and Step-by-step explanation:
It ensures that you don't accidently skip a step or get confused by which numbers are being used. By writing it down, it allows you to look back and see if you answer was correct or incorrect.
For example:
On a test, you need to do a complicated math problem that you know you can do in your head. It would still be a good idea to write down the process, so that you can see in front of you the numbers you get and results. If it is incorrect when checking over you answers, then you can go through the steps you made to see where you made a mistake.
#teamtrees #PAW (Plant And Water)
Answer:
Because when you need to use this information in the future it will be in your notebook/binder. When you study each lesson you will have the answers in your notes for when you do a Test or quiz. When doing math in your head it is called mental math but it is only used when needed.
Step-by-step explanation:
- chicken box
Pedro compró un minigimnasio para ejercitarse
en casa y mejorar su condición física. En la
compra le hicieron dos descuentos sucesivos del
30% y el 20%. Si ahorró S/ 352, ¿cuánto pagó?
Answers
Answer:
Pedro pagó $448
Step-by-step explanation:
Sea P el precio inicial de un objeto.
Si aplicamos un descuento del X%, entonces el nuevo precio del objeto es:
NP = P*(1 - X%/100%)
y lo que estamos ahorrando es:
P - NP
En este caso, primero tenemos un descuento del 30%, entonces:
NP = P*(1 - 30%/100%) = P*(1 - 0.3)
Luego tenemos otro descuento, esta vez del 20%, entonces:
NP' = NP*(1 - 20%/100%) = P*(1 - 0.3)*(1 - 20%/100%) = P*(1 - 0.3)*(1 - 0.2)
Lo que Pedro ahorra es igual a $352
entonces:
P - NP' = $352
P - P*(1 - 0.3)*(1 - 0.2) = $352
P*(1 - (1 - 0.3)*(1 - 0.2)) = $352
P*(1 - 0.56) = $352
P = $352/(1 - 0.56) = $800
Esto significa que el precio original era $800.
Y lo que pedro pago esta dado por la ecuación:
NP' = P*(1 - 0.2)*(1 - 0.3) = $800*(1 - 0.2)*(1 - 0.3) = $448.
Find the x- and y-intercepts on the graph.
y
100.
8
61
-
4
- 10 -8 70
2
4
6
8
Y
10
wwwwwwwww
– 101
x-intercept
(x, y) =
y-intercept
(x, y) =
A 14:-----------
Search
N
Answers
9514 1404 393
Answer:
x-intercept: (-5, 0)
y-intercept: (0, 5)
Step-by-step explanation:
The x-intercept is where the graph crosses the x-axis. The x-value there is -5. The y-value of any point on the x-axis is 0, so the point coordinates are (-5, 0).
The y-intercept is where the graph crosses the y-axis. The y-value there is 5. The x-value of any point on the y-axis is 0, so the point coordinates are (0, 5).
x-intercept: (-5, 0)y-intercept: (0, 5)i need help i dont know how to do this yet
Answers
Answer:
A=wl=4·7=28 answer is 28
Step-by-step explanation:
Answer:
the answer is 28
Step-by-step explanation:
you do lengthh times width
the length is 7 the width is 4
so 7 times 4 is 28
Find the sum of the arithmetic series given a1=8,a14=99,n=14.
Answers
Answer:
The sum of the series is 749
Step-by-step explanation:
Given
[tex]a_1 = 8[/tex]
[tex]a_{14} = 99[/tex]
[tex]n = 14[/tex]
Required
The sum of the series
This is calculated using:
[tex]S_n = \frac{n}{2}[a_1 + a_n][/tex]
Substitute 14 for n
[tex]S_{14} = \frac{14}{2}[a_1 + a_{14}][/tex]
[tex]S_{14} = 7[a_1 + a_{14}][/tex]
Substitute values for a1 and a14
[tex]S_{14} = 7[8 + 99][/tex]
[tex]S_{14} = 7*107[/tex]
[tex]S_{14} = 749[/tex]
Plz help plz ill give brainliest
A scientist is growing bacteria.
The number of bacterial cells triples every week.
There are currently 20 cells.
Which expression shows how to find the number of cells in 4 weeks?
A. f (4) = 3 ∙ 204
B. f (4) = 4 ∙ 203
C. f (4) = 20 ∙ 34
D. f (4) = 20 ∙ 43
Answers
Answer:
B. f (4) = 4 · [tex]20^{3}[/tex]
Step-by-step explanation:
I did the quiz too
PLEASE HELP I WILL MAKE YOU BRAINLIEST IF IT LETS ME
NO FAKE LINKS OR YOU WILL BE REPORTED
Answers
Answer:
I am almost postive it is B, D, E
Pls help solve this...No hacker links
Answers
Answer:
x=13
Step-by-step explanation:
18-5=13. You have to subtract 5 from 5 itself and then 18.
I worked it out
HELP ME PLEASE!!!!!!!
Answers
Answer:
here are the cordinates you need to mark :
Step-by-step explanation:
(1,15) : 1x,15y
(2,20) : 2x,20y
(3,35) : 3x,35y
(4,45) : 4x,45y
(5,70) : 5x,70y
Hope this helps :)
Find the slope and y-intercept of the equation.
y + 7 = 4x
slope: 7
&
y-intercept: 4
slope: 4
&
y-intercept: -7
slope: 4
&
y-intercept: 7
slope: -4
& y-intercept: 7
Answers
Answer:
slope: 4
Y-intercept: -7
Step-by-step explanation:
you would have to solve for y so you subtract the 7 on both sides. then it is in slope-intercept form which is y=mx+b where m is slope and b is the y-intercept. the slope would be 4 and the y-intercept would be -7
what is the area of the triangle 13,12,5
Answers
Answer:
area = 5
Step-by-step explanation:
Graph the following function on the axes provided.
Answers
Answer:
this may help you.look it once
Step-by-step explanation:
.
If y=
-x and x = -12, find y.
Answers
Answer:
y = - 3
Step-by-step explanation:
[tex]y = \frac{1}{4}x[/tex]
y = 0.25 · x
y = 0.25 · - 12
y = - 3
Jerry has $90 in his savings account. The interest rate is 10%, compounded annually. To the nearest cent, how much interest will he earn in 3 years
Answers
Answer:
27 cents
Step-by-step explanation:
10% of 90= 9
9x3=27
Answer:
p x t x r / 100
90 x 10 x 3 / 100
=27
What is the approximate number of wins for the four teams?
A) 200
B) 230
C) 240
D 250
Answers
answer
the answer is is is option a 200
Transparency and worksheet master lesson 4.2 page 166