Answer:
a) 752 medical files should be included.
b) 372 medical files should be included.
Step-by-step explanation:
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 z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is of:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
Question a:
This is n for which M = 0.03. We have no estimate, so we use [tex]\pi = 0.5[/tex]. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.03 = 1.645\sqrt{\frac{0.5*0.5}{n}}[/tex]
[tex]0.03\sqrt{n} = 1.645*0.5[/tex]
[tex]\sqrt{n} = \frac{1.645*0.5}{0.03}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.645*0.5}{0.03})^2[/tex]
[tex]n = 751.67[/tex]
Rounding up:
752 medical files should be included.
Question b:
Now we have that:
[tex]\pi = \frac{13}{90} = 0.1444[/tex]
So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.03 = 1.645\sqrt{\frac{0.1444*0.8556}{n}}[/tex]
[tex]0.03\sqrt{n} = 1.645\sqrt{0.1444*0.8556}[/tex]
[tex]\sqrt{n} = \frac{1.645\sqrt{0.1444*0.8556}}{0.03}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.645\sqrt{0.1444*0.8556}}{0.03})^2[/tex]
[tex]n = 371.5[/tex]
Rounding up:
372 medical files should be included.
An urn contains 12 balls, five of which are red. Selection of a red ball is desired and is therefore considered to be a success. If three balls are selected, what is the expected value of the distribution of the number of selected red balls
The expected value of the distribution of the number of selected red balls is 0.795.
What is the expected value?The expected value of the distribution is the mean or average of the possible outcomes.
There are 12 balls in an urn, five of which are crimson. The selection of a red ball is desired and hence considered a success.
In this case, the possible outcomes are 0, 1, 2, or 3 red balls.
To calculate the expected value, we need to find the probability of each outcome and multiply it by the value of the outcome.
The probability of selecting 0 red balls is :
[tex]$\frac{7}{12} \cdot \frac{6}{11} \cdot \frac{5}{10} = \frac{105}{660}$[/tex].
The probability of selecting 1 red ball is :
[tex]$3 \cdot \frac{5}{12} \cdot \frac{7}{11} \cdot \frac{6}{10} + 3 \cdot \frac{7}{12} \cdot \frac{5}{11} \cdot \frac{6}{10} + 3 \cdot \frac{7}{12} \cdot \frac{6}{11} \cdot \frac{5}{10} = \frac{315}{660}$[/tex].
The probability of selecting 2 red balls is
[tex]:$\dfrac{5}{12} \cdot \frac{7}{11} \cdot \frac{6}{10} + \frac{7}{12} \cdot \frac{5}{11} \cdot \frac{6}{10} + \frac{7}{12} \cdot \frac{6}{11} \cdot \frac{5}{10} = \frac{105}{660}$.[/tex]
The probability of selecting 3 red balls is
[tex]$\dfrac{5}{12} \cdot \frac{4}{11} \cdot \frac{3}{10} = \frac{15}{660}$[/tex]
The expected value is then :
[tex]$0 \cdot \frac{105}{660} + 1 \cdot \frac{315}{660} + 2 \cdot \frac{105}{660} + 3 \cdot \frac{15}{660} = \frac{525}{660} = \frac{175}{220} \approx \boxed{0.795}$[/tex]
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Question 6 of 11 Step 1 of 6 No Time Limit The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line, û = bo + bjx, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.
Price in Dollars 23 34 44 46 50
Number of Bids 1 2 4 9 10
Step 1 of 6: Find the estimated slope. Round your answer to three decimal places.
The estimated slope is approximately 2.344
The given table is presented as follows;
[tex]\begin{array}{ccc}Number \ of Bids &&Price \ in \ Dollars\\1&&23\\2&&34\\4&&44\\9&&46\\10&&50\end{array}[/tex]
The regression line formula to be considered = [tex]\bar u = b_0 + b\cdot \bar x[/tex]
The required parameter is;
The estimated slope
The method to find the estimate slope;
The least squares regression formula (method) is presented as follows;
[tex]\bar u = b_0 + b\cdot \bar x[/tex]
Where;
b₀ = The y-intercept
[tex]\mathbf{ b = \dfrac{\sum \left(x_i - \bar x\right) \times \left(u_i - \bar u\right) }{\sum \left(x_i - \bar x\right )^2 } = The \ estimated \ slope}[/tex]
From MS Excel, we have;
[tex]\bar x[/tex] = 5.2, [tex]\bar u[/tex] = 39.4
[tex]\sum \left(x_i - \bar x\right) \times \left(u_i - \bar u\right)[/tex] = 156.6
[tex]{\sum \left(x_i - \bar x\right )^2 }[/tex] = 66.8
Therefore;
The estimated slope, b = 156.6/66.8 ≈ 2.344 (by rounding the answer to three decimal places)
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please help me with geometry
Answer:
x = 5Step-by-step explanation:
triangol BCD = triangle BDA
so
3x - 1 = 34 - 2x
5x = 35
x = 35 : 5
x = 5Answer:
x = 7
Step-by-step explanation:
BD is an angle bisector , so
∠ ABD = ∠ DBC , that is
3x - 1 = 34 - 2x ( add 2x to both sides )
5x - 1 = 34 ( add 1 to both sides )
5x = 35 ( divide both sides by 5 )
x = 7
Show that Reſiz) = -Im(z)
Step-by-step explanation:
[tex]re(i(x + yi) = - im(x + yi) \\ re(xi - y) = - im(x + yi) \\ - y = - (y) \\ - y = - y \\ proved \: is \: correct[/tex]
If 1100 square centimeters of material is available to make a box with a square base and an open top, find the largest possible volume of the box. Round to two decimal places if necessary.
volume= a^2 * h
area= a^2+4ah
take the second equation, solve for h
4ah=1100-a^2
h=1100/4a -1/4 a now put that expression in volume equation for h.
YOu now have a volume expression as function of a.
take the derivative, set to zero, solve for a. Then put that value back into the volume equation, solve for Volume.
Cited from jiskha
Convert the following equation
into standard form.
y = 7 - 7x
[?]x + y = []
Answer:
[tex]y = 7 - 7x \\ y + 7x = 7 \\ 7x + y = 7[/tex]
Answer:
7x + y = 7
Step-by-step explanation:
The equation of a line in standard form is
Ax + By = C ( A is a positive integer and B, C are integers )
Given
y = 7 - 7x ( add 7x to both sides )
7x + y = 7 ← in standard form
Name three different ways a bar graph can be drawn.
3. Find the least common denominator for the group of denominators using the method of prime numbers. 45, 75, 63
We have to find LCM
3 | 45,75,63
3 | 15,25,21
5 | 5,25,7
5 | 1,5,7
7 | 1,1,7
LCM=3×3×5×5×7=1575
The least common denominator for the group of denominators using the method of prime numbers is 1575.
What is least common multiple?LCM stands for Least Common Multiple. It is a method to find the smallest common multiple between any two or more numbers. A factor is one of the numbers that multiplies by a whole number to get that number.
For the given situation,
The numbers are 45, 75, 63
Prime factors of 45 = [tex]3,3,5[/tex]
Prime factors of 75 = [tex]3,5,5[/tex]
Prime factors of 63 = [tex]3,3,7[/tex]
Then the LCM can be found by, first take the common factors then multiple the remaining factors as,
⇒ [tex](3)(3)(5)(5)(7)[/tex]
⇒ [tex]1575[/tex]
Hence we can conclude that the least common denominator for the group of denominators using the method of prime numbers is 1575.
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Given: AABC, AC = 5
m C = 90°
m A= 22°
Find: Perimeter of AABC
A
C
B
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Answer:
perimeter ≈ 12.4 units
Step-by-step explanation:
The side adjacent to the angle is given. The relationships useful for the other two sides are ...
Tan = Opposite/Adjacent
Cos = Adjacent/Hypotenuse
From these, we have ...
opposite = 5·tan(22°) ≈ 2.02
hypotenuse = 5/cos(22°) ≈ 5.39
Then the perimeter is ...
P = a + b + c = 2.02 + 5 + 5.39 = 12.41
The perimeter of ∆ABC is about 12.4 units.
Can someone please help me solve the equation?
Answer:
(0,0) is the x and y intercept of the function
Step-by-step explanation:
The parabola touches the x and y axis at 0
The x intercept is (0,0) and the y intercept is (0,0)
Answer:
(0, 0) is the x and y intercepts
Step-by-step explanation:
intercepts are where the curve of the equation contacts an axis
The equation is y = x²
evaluate (5^0-4^-1)×3/4
Answer:
[tex](5^{0} -4^{-1} )(\frac{3}{4} )\\\\=(1-\frac{1}{4^{1}} )(\frac{3}{4} )\\\\=(\frac{4}{4} -\frac{1}{4} )(\frac{3}{4} )\\\\=(\frac{3}{4} )(\frac{3}{4} )\\\\=\frac{9}{16}[/tex]
75% increase followed by 50% decrease is it greater than to original
Answer:
Set original amount = xAfter a 75% increase, it would become
x + 75%x = x + 0.75x = x(1 + 0.75) = 1.75x
After a 50% decrease, it would become
1.75x - 50%(1.75x) = 1.75x - 0.5(1.75x) = 1.75x - 0.875x = 0.875x = [tex]\frac{7}{8} x[/tex]
Because [tex]\frac{7}{8} x[/tex] is less than x, the new amount would be less than the original.
Lynbrook West, an apartment complex, has 100 two-bedroom units. The monthly profit (in dollars) realized from renting out x apartments is given by the following function. p(x)=-12x^2+2160x-59000 To maximize the monthly rental profit, how many units should be rented out? units What is the maximum monthly profit realizable?
Answer:
To maximize the monthly rental profit, 90 units should be rented out.
The maximum monthly profit realizable is $38,200.
Step-by-step explanation:
Vertex of a quadratic function:
Suppose we have a quadratic function in the following format:
[tex]f(x) = ax^{2} + bx + c[/tex]
It's vertex is the point [tex](x_{v}, y_{v})[/tex]
In which
[tex]x_{v} = -\frac{b}{2a}[/tex]
[tex]y_{v} = -\frac{\Delta}{4a}[/tex]
Where
[tex]\Delta = b^2-4ac[/tex]
If a<0, the vertex is a maximum point, that is, the maximum value happens at [tex]x_{v}[/tex], and it's value is [tex]y_{v}[/tex].
In this question:
Quadratic equation with [tex]a = -12, b = 2160, c = -59000[/tex]
To maximize the monthly rental profit, how many units should be rented out?
This is the x-value of the vertex, so:
[tex]x_{v} = -\frac{b}{2a} = -\frac{2160}{2(-12)} = \frac{2160}{24} = 90[/tex]
To maximize the monthly rental profit, 90 units should be rented out.
What is the maximum monthly profit realizable?
This is p(90). So
[tex]p(90) = -12(90)^2 + 2160(90) - 59000 = 38200[/tex]
The maximum monthly profit realizable is $38,200.
The cylinders shown are similar. What is the volume of the larger cylinder?
Step-by-step explanation:
Ratio of height (large to small) = ratio of radii (large to small).
(h / 14) = (8 / 2)
h / 14 = 4
h = 56
The height of the larger cylinder is 56m.
Volume of cylinder is
V = πr2h
V = π(8)2(56)
V = 3584π
If a teacher's guide to a popular SAT workbook is to be printed using a special type of paper, the guide must have at most 400 pages. If the publishing company charges 1 cent per page printed, what is the largest price, in dollars, that can be charged to print 20 copies of the workbook using the special paper?
Answer:
$80
Step-by-step explanation:
To find the largest price, assume that all 20 copies of the workbook will have 400 pages.
Since the company charges 1 cent per page, this means each workbook will cost 400 cents. This is equivalent to 4 dollars.
Find the total cost by multiplying this by 20:
20(4)
= 80
So, the largest price to print 20 copies is $80
Complete the coordinate table for the given equation.
Xy=-4
Step-by-step explanation:
X= -4,-2,2,4 (respectively)
Y=4,-4 (respectively)
hope it helps
(x
3
+y
3
)(xy
4
+7)
Answer:
question is not proper
Step-by-step explanation:
question is
a certain number plus two is five find the number
x=3
Step-by-step explanation:
x+2=5
x=5-2
x=3
Find the slope of the line passing through the points (9, 1) and (9,-4).
Answer:
slope is undefined
Step-by-step explanation:
(9, 1 ) and (9, - 4 )
Since the x- coordinates of the 2 points are 9, then the line is vertical and parallel to the y- axis with slope being undefined.
Slope is the change in y over the change in x.
Slope = (-4 - 1) / (9 -9) = -5/0 you cannot divide by 0,so the slope is undefined. This means it is a vertical line
Please help !!! Plzzzz
Explanation:
Because we have a midsegment, this means that it is half as long as the side it's parallel to. You can think of "mid" as "middle" and that could lead to "halfway" to remember to take half.
So z = 14/2 = 7
compute (-12)+(-8)+30
Answer:
10
Step-by-step explanation:
(-12) + (-8) +30
-(12+8)+30
-20 + 30
10
A sample of 900 computer chips revealed that 61% of the chips fail in the first 1000 hours of their use. The company's promotional literature claimed that under 64% fail in the first 1000 hours of their use. Is there sufficient evidence at the 0.02 level to support the company's claim
Answer:
The p-value of the test is 0.0301 > 0.02, which means that there is not sufficient evidence at the 0.02 level to support the company's claim.
Step-by-step explanation:
The company's promotional literature claimed that under 64% fail in the first 1000 hours of their use.
At the null hypothesis, we test if the proportion is of at least 64%, that is:
[tex]H_0: p \geq 0.64[/tex]
At the alternative hypothesis, we test if the proportion is of less than 64%, that is:
[tex]H_1: p < 0.64[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
64% is tested at the null hypothesis:
This means that [tex]\mu = 0.64, \sigma = \sqrt{0.64*0.36}[/tex]
A sample of 900 computer chips revealed that 61% of the chips fail in the first 1000 hours of their use.
This means that [tex]n = 900, X = 0.61[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{0.61 - 0.64}{\frac{\sqrt{0.64*0.36}}{\sqrt{900}}}[/tex]
[tex]z = -1.88[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a sample proportion below 0.61, which is the p-value of z = -1.88.
Looking at the z-table, z = -1.88 has a p-value of 0.0301.
The p-value of the test is 0.0301 > 0.02, which means that there is not sufficient evidence at the 0.02 level to support the company's claim.
Question Which of the following is a benefit of using email to communicate at work ? a) You can express yourself in a limited number of characters b) You don't have to worry about using proper grammar. c) You always get a response right away. d ) You can reach a large audience with one communication .
Answer:
d) you can reach a large audience with one communication
Step-by-step explanation:
common sense
plez halppp mehh ;-;
Answer:
False
True
True
Step-by-step explanation:
Angle 1 cannot be equal to angle 4. Even by just viewing one can see that they can't be equal.
Angle 1 and 2 when combined give a 90 degree angle going from a to c.
Angle 3 and 4 form a 180 degree angle.
HOPE THIS HELPED
If Y / 4 - 12 = 3.5, what is the value of y?
prove that Sin^6 ϴ-cos^6ϴ=(2Sin^2ϴ-1)(cos^2ϴ+sin^4ϴ) please sove step by step with language it is opt maths question please sove i will mark you the best
Answer:
hshdkKnfbsjfjznd jzkz e zkkfkd
Given the parent graph h(x) = x, what happens when it is changed to h(x + 9)?
Answer:
If the parent graph is h(x) = x, then h(x+9) would actually be shifting the graph 9 units to the LEFT.
Let me know if this helps!
Determine whether the integral is divergent or convergent. If it is convergent, evaluate it.
[infinity]
â« e^-1.3x dx
1
Knowing that AQPT = AARZ, a congruent side pair is:
Answer:
A. QT ≅ AZ
Step-by-step explanation:
When writing a congruence statement of two triangles, the order of arrangement of the letters used in naming the triangles are carefully considered. Corresponding sides and angles of both triangles are arranged accordingly in the order they appear.
Given that ∆QPT ≅ ∆ARZ, we have the following sides that correspond and are congruent to each other:
QP ≅ AR
PT ≅ RZ
QT ≅ AZ
The only correct one given in the options given above is QT ≅ AZ
Infues Gentamicin 100 mg in 100ml in 15 minutes. What will you set the infusion pump at ml/hr
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Answer:
400 mL/h
Step-by-step explanation:
The required rate is ...
(100 mL)/(1/4 h) = 100×(4/1) mL/h = 400 mL/h
