Answer:
The smallest sample size that we should consider is 68.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Standard deviation of 10 minutes.
This means that [tex]\mu = 10[/tex]
What is the smallest sample size that we should consider?
This is n for which M = 2. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]2 = 1.645\frac{10}{\sqrt{n}}[/tex]
[tex]2\sqrt{n} = 1.645*10[/tex]
[tex]\sqrt{n} = 1.645*5[/tex]
[tex](\sqrt{n})^2 = (1.645*5)^2[/tex]
[tex]n = 67.7[/tex]
Rounding up:
The smallest sample size that we should consider is 68.
Using a graphical method, solve the quadratic equation:
-X2 - 2x + 3 = 0
2-2x+3=0
5-2x=0
-5 -5
-2x=-5
/-2 /-2
x=2.5
---
hope it helps
sorry if I'm wrong
the X confused me
If x = 2, then which of the following equations makes a TRUE statement?
a.4x + 9 = 20
b.-4x + 5 = -3
c.-3x + 15 = 21
d.5x – 15 = 5
Answer:
Answer is B
Step-by-step explanation: −4x + 5= −3
1. Subtract 5 from both sides −4x +5 −5 = −3 −5
2. You remain with this −4x = −8
3. Divide both side by -4. -4x/-4 = -8/-4
4. Answer will be x = 2
If y varies directly with x, and y= 4/5 when x= 5:
Find the variation constant, k
Answer:
k = 4/25 or 0.16
Step-by-step explanation:
Given the following data;
y = 4/5
x = 5
To find the variation constant, k;
y is directly proportional to x
Mathematically, y = kx
Substituting into the formula, we have;
4/5 = k5
Cross-multiplying, we have;
4 = 25k
k = 4/25
An engineer stands 50 feet away from a building with a surveying device mounted on a tripod. if
the surveying device is 5 feet above the ground and the angle of elevation is 50°, find how tall is
the building.
Answer:
The building is 64.6 feet tall.
Step-by-step explanation:
To determine the height of the building, let the height from the top of the building to the top of the tripod be represented by x. So that;
Height of the building = x + 5
But,
Tan θ = [tex]\frac{opposite}{adjacent}[/tex]
Tan [tex]50^{o}[/tex] = [tex]\frac{x}{50}[/tex]
x = 50 x Tan [tex]50^{o}[/tex]
= 50 x 1.1918
= 59.59
x = 59.59
Height of the building = x + 5
= 59.59 + 5
= 64.6 ft
The height of the building is 64.6 feet.
Your teacher has disabled instant marking. Your marks will appear after the due date.
There are 1200 students at a school.
Each student has either a packed lunch or a school dinner.
62% of the students have school dinners.
55% of the students are girls.
45% of the girls have packed lunches.
62%=
How many boys have school dinners?
You must show all your working.
Answer:
38
Step-by-step explanation: 100 - 62= 38
I am not sure of my answer tho
Pls help I’ll pay u 30$ if it’s right
Answer:
8 5 7 1 3 2 4 6
Step-by-step explanation:
my Cashsap kinqcollin
HELP ASAP!!! A spinner has three sections colored green, purple, and pink. If the spinner is spun twice, how many branches would the tree diagram that represents this situation have? 6 5 9 12
Answer:
The answer is 9.
Answer:
The answer is 9
Step-by-step explanation:
I got it right on the quiz
Question 14
Find the volume of this sphere. Round to the nearest hundredth.
6.5 cm
cm cubed
Answer:
1150.35
Step-by-step explanation:
Will give brainliest
Find the probability that a randomly
selected point within the circle falls
in the white area.
W
r = 4 cm
4√2 cm
[? ]%
Round to the nearest tenth of a percent.
Answer:
The probability that a randomly selected point within the circle falls in the white area is approximately 36.3%
Step-by-step explanation:
The given parameters of the area are;
The length of the radius of the circle, r = 4 cm
The length of the side of the inscribed quadrilateral, s = 4·√2 cm
The diagonals of the inscribed quadrilateral = 2 × The radius of the circle
∴ The diagonals of the inscribed quadrilateral are equal and given that the sides of the quadrilateral are equal, the quadrilateral is a square
The probability that a randomly selected point within the circle is white is given by the ratio of the white area to the brown square area as follows;
The white area = The total area - The area brown square
The total area, A = The area of the circle with radius, r = π·r²
∴ A = π·(4 cm)² = 16·π cm²
The area of the brown square, Asq = s² = 4·√2 cm × 4·√2 cm = 32 cm²
The white area, Aw = 16·π cm² - 32 cm² = 16·(π - 2) cm²
The probability that a randomly selected point within the circle falls in the white area is therefore;
[tex]P(W) = \dfrac{A_W}{T_A} = \dfrac{16 \cdot (\pi - 2) \, cm^2}{16 \cdot \pi \, cm^2 } \times 100= \left (1 - \dfrac{2}{\pi}\right) \times 100 \approx 36.338022763241865692 \%[/tex]
By rounding to the nearest tenth of a percent, we have;
The probability that a randomly selected point within the circle falls in the white area, P(W) ≈ 38.3%.
its very easy just try it
Answer:
it is biased
Step-by-step explanation:
40x +16y = ( + )
plz help me
Answer:
Write in Slope-Intercept Form
Graph
Find the x and y Intercepts
Find the Slope
Find the Slope and y-intercept
Write in y=mx+b Form
Write in Standard Form
Given P(A) = 0.4, P(B) = 0.58 and P(A|B) = 0.5, find the value of
P(A and B), rounding to the nearest thousandth, if necessary.
By definition of conditional probability,
P(A | B) = P(A and B) / P(B)
so
P(A and B) = P(A | B) P(B) = 0.5 × 0.58 = 0.29
is 2/3 equal to 2/4 ? if not is it greater
Answer:
Equivalent fraction of a given fraction is got by multiplying or dividing its numerator and denominator by the same whole number. For example, if we multiply the numerator and denominator of 2/3 by 4 we get. 2/3 = 2×4 / 3×4 = 8/12 which is an equivalent fraction of 2/3.
Step-by-step explanation:
PLEASE ANSWER EXTRA POINTS AND NAMED BRAINLIEST

Answer:
5,8 8,3
Step-by-step explanation:
hoped this helped <33
An experiment examined the impact of THC (the active ingredient in marijuana) on various physiological and psychological variables. The study recruited a sample of 18 young adults who were habitual marijuana smokers. Subjects came to the lab 3 times, each time smoking a different marijuana cigarette: one with 3.9% THC, one with 1.8% THC, and one with no THC (a placebo). The order of the conditions was randomized in a double-blind design. At the start of each session, no subject reported being "high." After smoking the cigarette, participants rated how "high" they felt, using a positive continuous scale (0 representing not at all "high"). For the placebo condition, participants reported a mean "high" feeling of 11.3, with a standard deviation of 15.5. A 95% confidence interval for the population mean feeling of "high" after smoking a placebo marijuana cigarette is
Answer:
OOO
Step-by-step explanation:
What must be true in order to find a sum for an infinite geometric series?
Answer:
That’s just your millennial snowflake brain being unable to comprehend real work. My grandpa lost both his thumbs to frostbite while walking 29.67 kilomiles to school in 10 feet of snow in the summer uphill both ways and he could still wield any tool known to man. And he did so for 83 and a half years until they forced him to retire because he was making all the other workers look like pansies. When he was told he was being forced to retire, he marched into the CEO’s office and declared “I’d rather be dead than a deadbeat.” Then he dropped dead on the spot. Now that’s loyalty!
Generating Equivalent Expressions
Simplify the expression
by applying the distributive property & combining like terms.
Show work.
6(x + 4y) + 3x - 20y
Answer:
9x +4y
Step-by-step explanation:
step 1 : parentheses are priorities
so multiple the 6 to the parentheses
6x + 24y +3x -20y
combine the x's together
6x +3x + 24y -20y
9x + 4 y
Answer:
[tex]9x + 4y[/tex]
Step-by-step explanation:
1) Expand by distributing term.
[tex]6x + 24y + 3x - 20y[/tex]
2) Collect like terms.
[tex](6x + 3x) + (24y - 20y)[/tex]
3) Simplify.
[tex]9x + 4y[/tex]
Hence, the answer is 9x + 4y.
Use inverse trigonometric functions to solve each problem.
A flag pole 30 feet tall casts a shadow of 50 feet on the ground. Find,
to the nearest tenth of a degree, the angle of elevation of the sun.
a.30°
b.31°
c.60°
d.61°
Answer:
BBBBBBBBBB
Step-by-step explanation:
Which sign makes this number sentence true?
|-6| __ |6|
A. >
B. <
C. =
D.
Answer:
C. =
Step-by-step explanation:
whenever you have | | It will always be positive so -6 turns to 6 and that makes it equal.
BRAINLIEST FOR CORRECT ANSWER, IM FAILING SCHOOL AND NEED HELP ASAP. EVEN OFFICIAL HELP COUNTS
Answer:
80
Step-by-step explanation:
sorry if wrong
3. P343. 13. A sociologist is interested in surveying workers in computer-related jobs to estimate the proportion of such workers who has changed jobs within the past years. (a) In the absence of preliminary data, how large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05? (b) In a sample of 100 workers, 20 of them had changed jobs within the past year. Find a 95% confidence interval for the proportion of workers who have changed jobs within the past year. (c) Based on the data in part (b), estimate the sample size needed so that the 95% confidence interval will specify the proportion to within ±0.05.
Answer:
a) A sample of 385 must be taken.
b) The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).
c) A sample of 246 is needed.
Step-by-step explanation:
Question a:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
Absence of preliminary data:
This means that we use [tex]\pi = 0.5[/tex], which is when the largest sample will be needed.
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
How large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05?
A sample of n must be taken.
n is found when [tex]M = 0.05[/tex]. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]
[tex]0.05\sqrt{n} = 1.96*0.5[/tex]
Dividing both sides by 0.05
[tex]\sqrt{n} = 1.96*10[/tex]
[tex](\sqrt{n})^2 = (19.6)^2[/tex]
[tex]n = 384.16[/tex]
Rounding up,
A sample of 385 must be taken.
Question b:
In a sample of 100 workers, 20 of them had changed jobs within the past year.
This means that [tex]n = 100, \pi = \frac{20}{100} = 0.2[/tex]
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 - 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.1216[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 + 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.2784[/tex]
The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).
Question c:
Same procedure as question a, just with [tex]\pi = 0.2[/tex]
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.05 = 1.96\sqrt{\frac{0.2*0.8}{n}}[/tex]
[tex]0.05\sqrt{n} = 1.96\sqrt{0.2*0.8}[/tex]
[tex]\sqrt{n} = \frac{1.96\sqrt{0.2*0.8}}{0.05}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.2*0.8}}{0.05})^2[/tex]
[tex]n = 245.8[/tex]
Rounding up
A sample of 246 is needed.
A ride in an amusement park features a swinging ship suspended from a height of 50 feet. The motion of the ship can be modeled by the graph below, where x represents the time, in seconds, since the start of the ride, and f(x) represents the angle, in radians, that the center of the ship makes with respect to the equilibrium position.
Select all the correct answers.
Answer: The first and last options are correct.
f(x) = pi/4 cos (pix/5 - pi/2)
f(x) = pi/4 sin (pix/5)
Step-by-step explanation
The graph shows that A = pi/4.
B = 10, so the period = 2pi/10 = pi/5.
sin and cos are cofunctions, so a phase shift of -pi/2 makes the two functions equal to each other.
Hope this helps :)
The correct answer is f(x) = π/4 cos (πx/5 - π/2) and f(x) = π/4 sin (πx/5).
option (A) and (D) are correct.
It is given that height of 50 feet and graph is given.
It is to find f(x).
What is graph?Graph is a mathematical representation of a network and it describes the relationship between lines and points.
The graph shows that A = π/4.
B = 10, so the period = 2π/10 = π/5.
sin and cos are co-functions, so a phase shift of -π/2 makes the two functions equal to each other.
So, the option are (A) and (D).
Learn more about graph here:
https://brainly.com/question/23004564
#SPJ2
Subtract 11x - 4y from the sum of 15x + 15y and - 18x + 15y.
Answer:
-14x + 34y
Step-by-step explanation:
First, find the sum of the two expressions by adding like terms:
(15x + 15y) + (-18x + 15y)
= -3x + 30y
Now, subtract 11x - 4y, again by combining like terms:
(-3x + 30y) - (11x - 4y)
= -14x + 34y
So, the answer is -14x + 34y
BRAINLIEST ACED AND EXPERT PLS HELP
Answer:
420
Step-by-step explanation:
9, 14, 12,17,15, 20,18
what is the rule for the following pattern?
Someone please help me answer this!!
Answer:
a = 15yd is the answer.
Step-by-step explanation:
a = ?
b = 8yd
c = 17yd
By using the Pythagoras theorem,
a² + b² = c²
a² + 8² = 17²
a² + 64 = 289
a² = 289 - 64
a² = 225
a = 15
∴ a = 15yd is the length of the missing leg.
After painting 3/8 of a fence he finds that he has painted 15 feet
Answer:
whats the question? theres no context other than that little bit
Answer:
The fence is 40 feet long.
Step-by-step explanation:
I suppose the question is "What is the length of the entire fence?"
Formula
3/8 x = 15 Multiply both sides by 8
8*(3/8)x = 15*8 Cancel
3x = 120 Divide by 3
3x/3 = 120/3
x = 40
13.068 the same as 13.608
Answer:
No its not
Step-by-step explanation:
13.603 is more then 13.068
The graph for y≥-3.
true
false
helpp me
Answer:
I think it's false
Step-by-step explanation
You deposit $500 at 6% interest annually. After 6 months, how much money will you earn?
