Answer: The required sample size = 97
Step-by-step explanation:
If prior population standard deviation is known, then the minimum sample size can be computed as:
[tex]n=(\frac{z^*\times\sigma}{E})^2[/tex]
,where z* = critical z-value
[tex]\sigma[/tex] = population standard deviation
E = Margin of error
As per given,
[tex]\sigma=20,\ E= 4[/tex]
Critical value for 95% confidence = 1.96
[tex]n=(\frac{1.96\times20}{4})^2\\= (1.96\times 5)^2\\= (9.8)^2\\=96.04\approx97[/tex]
Hence, the required sample size = 97
A desktop is shaped like a semicircle with a diameter of 28 what is the area of the desktop?
Answer:
307.72
Step-by-step explanation:
if the diameter is 28 then the radius is 14 (half of the diameter)
Help me on this question please. Thx
Of the men in the survey, what percent of them prefer movies? Write your answer as a percent and round to one decimal place.
Answer:
40%Step-by-step explanation:
There are 20 men and 8 of them prefer movies.
P = 8/20 = 0.4 = 40%QUICK!! GIVING BRAINLIEST TO CORRECT ANSWER QUICK!!
Answer:
Im fairly sure it is 45ft^3
Answer:
[tex]45ft^{2}[/tex]
Step-by-step explanation:
V=L*W*H
A boy collects a total of 316 stamps, sticker and coins altogether. He collects 4 times as many stamps as stickers. There are 46 coins. How many stamps are there?
Answer:
216 stamps
Step-by-step explanation:
Stamps =4x
stickers=x
coins=46
4x+x+46=316 (stamps, stickers and coins)
5x=270
x=54 (stickers)
4x=stamps
4(54)=stamps
216=stamps
check answer
54 (stickers)+216(stamps)+46 (coins)=316
316=316
pls help!! Need the answer asap!!
Step-by-step explanation:
19+k=90°
k=90-17
k=71°
stay safe healthy and happy .15 POINTS. Ronna is estimating the amount of a 15% tip for a $20.36 bill. Her friend Suri said that $2 is a good estimate. Do you agree? Explain.
Hi
It's not a good estimation. 2 is 10% of 20, so 5% is 1 dollar.
As the bill is above 20, and 15 = 10+5 , so 15% is at least more than 3.
So 3 would be a better estimation.
In fact, 15% of 20.36 is : 20.36 *0.15 = 3.054
PLEASEEEEEE IM BEGGING SOMEONE PLEASEEEE HELPPPP PLEASEEEEE PLEASEEEEE SOEMONE HELPPPP PLEASEEEEEEEEEEEEEEEEEEEE
Answer:
8 nachos and 5 hot dogs
Step-by-step explanation:
Let x equal number of nachos
let y equal number of how dogs
1.5x + 2y = 22
x + y = 13
y = 13 - x
1.5x + 2(13 - x) = 22
1.5x + 26 - 2x = 22
1.5x - 2x = 22 - 26
-0.5x = - 4
x = -4/-0.5
x = 8
y = 13 - x
y = 13 - 8
y = 5
evaluate -5/z for z=5
Answer:-5/z ; z=5 solution -1
Step-by-step explanation:
-5/5
For the function f(x) = 7/2x-16, what is the difference quotient for all nonzero values of h?
Answer:
[tex]\frac{f(x + h) - f(x)}{ h} = \frac{7}{2}[/tex]
Step-by-step explanation:
Given
[tex]f(x) = \frac{7}{2}x - 16[/tex]
Required
The difference quotient for h
The difference quotient is calculated as:
[tex]\frac{f(x + h) - f(x)}{ h}[/tex]
Calculate f(x + h)
[tex]f(x) = \frac{7}{2}x - 16[/tex]
[tex]f(x+h) = \frac{7}{2}(x+h) - 16[/tex]
[tex]f(x+h) = \frac{7}{2}x+ \frac{7}{2}h- 16[/tex]
The numerator of [tex]\frac{f(x + h) - f(x)}{ h}[/tex] is:
[tex]f(x + h) - f(x) = \frac{7}{2}x+ \frac{7}{2}h- 16 -(\frac{7}{2}x - 16)[/tex]
[tex]f(x + h) - f(x) = \frac{7}{2}x+ \frac{7}{2}h- 16 -\frac{7}{2}x + 16[/tex]
Collect like terms
[tex]f(x + h) - f(x) = \frac{7}{2}x -\frac{7}{2}x + \frac{7}{2}h- 16 + 16[/tex]
[tex]f(x + h) - f(x) = \frac{7}{2}h[/tex]
So, we have:
[tex]\frac{f(x + h) - f(x)}{ h} = \frac{7}{2}h \div h[/tex]
Rewrite as:
[tex]\frac{f(x + h) - f(x)}{ h} = \frac{7}{2}h * \frac{1}{h}[/tex]
[tex]\frac{f(x + h) - f(x)}{ h} = \frac{7}{2}[/tex]
Answer:
It is A.
Step-by-step explanation:
Just took the test
The weight of laboratory grasshoppers follows a Normal distribution, with a mean of 90 grams and a standard deviation of 2 grams. What percentage of the grasshoppers weigh between 86 grams and 94 grams
Answer:
95.44% of the grasshoppers weigh between 86 grams and 94 grams.
Step-by-step explanation:
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.
Mean of 90 grams and a standard deviation of 2 grams.
This means that [tex]\mu = 90, \sigma = 2[/tex]
What percentage of the grasshoppers weigh between 86 grams and 94 grams?
The proportion is the p-value of Z when X = 94 subtracted by the p-value of Z when X = 86. So
X = 94
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{94 - 90}{2}[/tex]
[tex]Z = 2[/tex]
[tex]Z = 2[/tex] has a p-value of 0.9772.
X = 86
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{86 - 90}{2}[/tex]
[tex]Z = -2[/tex]
[tex]Z = -2[/tex] has a p-value of 0.0228.
0.9772 - 0.0228 = 0.9544
0.9544*100% = 95.44%
95.44% of the grasshoppers weigh between 86 grams and 94 grams.
Which factorization is equivalent to this expression?
−20x − 5y
Answer:
[tex] - 20x - 5y \\ - (20x + 5y) \\ = - 5(4x + y)[/tex]
If anyone could help it would be great
Answer:
See the pictureStep-by-step explanation:
Solved, green filled arrows in the pictureProblem Solving
Find the exact solution of each equation for 0 and greater than or equal to q and less than 2pi.
4 cos^2q=3
can anyone help me with this?
Answer:
120 degrees is x
Step-by-step explanation:
because both are equal angles
btw nice Pikachu meme
If you know how to solve this, Please answer it. Thank You
The first one to answer the question right, will get Brainlist!
I PROMISE!!!!!
y = ( x + 9 )^2 - 2
................................
................................
Can someone please help and explain how to use the Pythagorean Theorem to prove a triangle is a right triangle.
Hi there!
For the Pythagorean Theorem, basically you just need to apply this formula: a^2 + b^2 = c^2
And then find the root of the hypotenuse.
For example,
15^2 + 8^2 = the hypotenuse^2
Which equals, 225 + 64 = 289
Square root of 289 = 17
Please mark me brainliest if this helps!
Have a wonderful day!
PLEASE HELP (failing this class and this is a 100 point assignment) (i mark brainlist)
Questions
The distances covered by each of two runners during the first 21 minutes of a race are
shown in the graph below. The time at which one runner passes the other is between
(A 2 minutes and 3 minutes
(B 6 minutes and 9 minutes
(C 9 minutes and 12 minutes
(D 18 minutes and 21 minutes
Answer: 9 minutes and 12 minutes
Step-by-step explanation:
Please help meeeeeeee
Answer:
5040
Step-by-step explanation:
This is a problem of permutation where one has to arrange all the letters of the word taken all at a time. Since in N lettered word if all the letters are different then it can be arranged in N! ways i.e factorial N ways.
In the problem mentioned given
Word : Musical
number of words = 7 (all the words are different)
Number of ways to arrange it = 7!
7*6*5*4*3*2*1 = 5040
Hence 5040 is the answer!
II. Write whether each number is an EXPRESSION or an EQUATION.
11.
2 + 5
12.
2 + 5 = 7
Ć XLN13.
4x = 12
14.
X + 25
15.
16-6 = 10
Answer:
11. Expression
12. Equation
13. Equation
14. Expression
15. Equation
Step-by-step explanation:
Expression:
Has no equal sign.
Equation:
Has equal sign.
11. 2 + 5
14. X + 25
Those which do not have the equal sign are expressions.
12. 2 + 5 = 7
13. 4x = 12
15. 16 - 6 = 10
Those with the equal sign are equations.
Round 893.38 to the nearest tenth
there are 420 students in a school 1/3 if the population is made up of girl
In a math class with 20 students, a test was given the same day that an assignment was due. There were 11 students who passed the test and 15 students who completed the assignment. There were 9 students who passed the test and also completed the assignment. What is the probability that a student chosen randomly from the class failed the test and did not complete the homework?
Answer: 3/20 or .15
Step-by-step explanation:
Which numbers are irrational? Select all that apply.
Answer:
I believe Option 1, 2 and 4 are all irrational numbers Hope this helps
Step-by-step explanation:
The distance from Kevin's home to his school is 2 kilometers. Adrian lives 750
meters from the same school. How much closer does Adrian live to school than
Kevin?
1>) 250 meters
1>) 550 meters
» 1,250 meters
2,750 meters
Answer:
see my explanation!!
Step-by-step explanation:
2000-750=1250m
Need help with this math question 15 points
Brody deposited $500 into an account that earns 4.2% interest compounded annually. He makes no additional deposits and no withdrawals. How much interest will the account have earned after 7 years?
A $167
B $420
C $542
D $665
Explain correctly. No nonsense, please.
Thank you
Find the simple interest on an investment of $3500 for 2.5 years at
5.5% per annum.
$428.52
$482.52
$418.25
$481.25
Answer:
$481.25
Step-by-step explanation:
The formula for simple interest is i = p*r*t, in which p is the principal, r is the interest rate as a decimal fraction, and t is the time in years.
Here p = $3500, r = 0.055 and t =2.5 yrs, and so the simple interest is
i = ($3500.00)(0.055)(2.5 yr), or
i = $481.25
y is directly proportional ( x+2)²
when x = 8 y= 250
find y when x = 4
Answer:
y=90 when x=4
Step-by-step explanation:
We are given that
[tex]y\propto (x+2)^2[/tex]
When x=8 and y=250
We have to find the value of y when x=4
[tex]y=k(x+2)^2[/tex]
Where k= Proportionality constant
Substitute the values
[tex]250=k(8+2)^2[/tex]
[tex]250=100k[/tex]
[tex]k=\frac{250}{100}[/tex]
[tex]k=5/2[/tex]
Now, substitute x=4 and k=5/2
Then, we get
[tex]y=\frac{5}{2}(4+2)^2[/tex]
[tex]y=\frac{5}{2}\times 36[/tex]
[tex]y=90[/tex]