Answer:
0.0726 = 7.26% probability that the proportion of Grammy award winners will differ from the singers proportion by greater than 4%
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 49% of American singers are Grammy award winners.
This means that [tex]p = 0.49[/tex]
Sample of size 502
This means that [tex]n = 502[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.49[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.49*0.51}{502}} = 0.0223[/tex]
What is the probability that the proportion of Grammy award winners will differ from the singers proportion by greater than 4%?
Proportion below 49% - 4% = 45% or above 49% + 4% = 53%. Since the normal distribution is symmetric, these probabilities are equal, so we find one of them and multiply by 2.
Probability the proportion is below 45%
p-value of Z when X = 0.45. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.45 - 0.49}{0.0223}[/tex]
[tex]Z = -1.79[/tex]
[tex]Z = -1.79[/tex] has a p-value of 0.0363.
2*0.0363 = 0.0726
0.0726 = 7.26% probability that the proportion of Grammy award winners will differ from the singers proportion by greater than 4%
A math instructor claims that college women have more credit card debt than college men. She conducts a random sample of 38 college men and 32 college women, determines their average credit card debt, and obtains the following statistics:
women n1 =32 x1= 781 s1 = 1489 men n2 = 38 x2 = 435 s2 = 1026
Test the claim that college women have more credit card debt than college men at the a = .05 level of significance. Assume unequal variances.
Answer:
There is no significant evidence to support the claim that college women have more credit card debt than college men
Step-by-step explanation:
Given :
women n1 =32 x1= 781 s1 = 1489 men n2 = 38 x2 = 435 s2 = 1026
H0 : μ1 = μ2
H0 : μ1 > μ2
Assume unequal variance :
The test statistic :
(x1 - x2) / √(s1²/n1) + (s2²/n2)
T= (781 - 435) / √(1489²/32) + (1026²/38)
T = 346 / 311.42740
Test statistic = 1.111
Degree of freedom, df
(s1²/n1+s2²/n2)²÷1/(n1-1)*(s1²/n1)²+1/(n2-1)*(s2²/n2)²
The Pvalue :
(s1²/n1+s2²/n2)² = ((1489²/32) + (1026²/38))² = 9406484230.6884765625
1/(n1-1)*(s1²/n1)²+1/(n2-1)*(s2²/n2)²:
1/31(1489^2/32)^2 + 1/37(1026^2/38)^2 = 1.755926E8
df = 9406484230.6884765625 / 1.755926E8 = 53.569
df = 54
The Pvalue, from t score ;
Pvalue(1.111, 54) = 0.136
Pvalue > α ; Hence, we fail to reject the null ; There is no significant evidence to support the claim that college women have more credit card debt than college men
A basketball player has a 0.498 probability of making a three-point shot. What is the probability that it takes the player 4 tries to make a three-point shot? (Round your answer to three decimals if necessary.)
Answer:
$1
Step-by-step explanation:
because of the dollar it makes sense to be a dollar
Ralph bought a computer monitor with an area of 384 square inches. The length of the monitor is six times the quantity of five less than half its width.
Complete the equation that can be used to determine the dimensions of the monitor in terms of its width, w.
Answer:
w= 103.5 inches
Step-by-step explanation:
384=w+3w-30
414=4w
w=414/4=103.5 inches
Answer:
first drop box 384
second drop box 3
third drop boc 30
384 = 3 [tex]w^{2}[/tex] – 30 w
Step-by-step explanation:
Correct answer on Plato/Edmentum test
find the least common multiple of two two-digit numbers. SHOW WORK
Answer:
The LCM of 20 and 30 is 60.
Step-by-step explanation:
LCM means the least common multiple.
The LCM of two numbers means the least multiple both numbers share.
Use the listing method:
Multiples of 20:
20, 40, 60, 80, 100, ......
Multiples of 30:
30, 60, 90, 120, 150, ...
The LCM is 60 because that is the least common multiple 20 and 30 have.
Hope this helps
The area of a circle is 3.142cm square.find the radius and diameter of the circle
Answer:
50.24 or 50.272
Step-by-step explanation:
Square radius and then times by 3.14 or 3.142
4^2*3.14 = 50.24
4^2*3.142 = 50.272
Identify the effect on the graph of replacing f(x) by A f(x)
Answer:
See explanation
Step-by-step explanation:
Required
Effect of replacing [tex]f(x)[/tex] with [tex]f(x - h)[/tex]
f(x) is represented as: (x,y)
While
f(x - h) is represented as (x - h, y)
Notice the difference in both is that, the x value in f(x - h) is reduced by a constant h while the y value remain unchanged.
This means that the graph of f(x) will shift horizontally (i.e. along the x-axis) to the left by h units
If f(x) is a linear function, what is the value of n?
х
_4
f(x)
---25
-10
-1
n
20
2
оооо
9
Step-by-step explanation:
You can simply plot these points on a graph and see where the line goes. It go
Use the graph to find the y-intercept and axis of symmetry
Answer:
axis of symmetry=-2
y intercept=(0,-1)
Need help on the last problem
no. of right answers = 60
no. of wrong answers = 40
Test scores for a Statistics class have a mean of 78 with a standard deviation of 6. Suppose a student gets an 81 on that test. What is the z-score for that grade?
Answer:
0.3209
in case you dont know A z-score tells you if the distribution it comes from is normal.
Step-by-step explanation:
to
W
3 62 Average Speed During the first part of a 6-hour
trip, you travel 240 miles at an average speed of r
miles per hour. For the next 72 miles of the trip, you
?
increase your speed by 10 miles per hour. What were
your two average speeds?
nd
69
How to solve
Answer:
40 and 10.33
Step-by-step explanation:
240÷6=40.. 72-10=62 62÷6=10.33
A total of $20,000 is invested at an annual interest rate of 6%. No matter how many years this
money is invested, what is the best investment plan to earn the most money in the end?
Compounded continuously
Compounded daily
Compounded quarterly
Compounded monthly
Which of the following indicates that Triangle ABC and Triangle DEF are similar?
Answer:
D
Step-by-step explanation:
The symbol ~ means similarity (same shapes, not same size)
Can you answer this an help me with this question an others ??
Answer:
D. The y-intercept of the new graph would shift down 2 units.
Step-by-step explanation:
y = -9x + 3 has a y-intercept of 3 (0, 3).
y = -9x + 1 has a y-intercept of 1 (0, 1).
3 - 1 = 2
So, down two units.
There's a three in the tens
placed
The digit is the ones places is
third multiple of three
It is a two-digit number
Answer:
That number is 39
An urn has 21 balls that are identical except that 8 are white, 7 are red, and 6 are blue. What is the probability that all are white if 3 are selected randomly without replacement?
Answer:
.0421
about 4.21%
Step-by-step explanation:
[tex]\frac{{8\choose3}}{{21\choose3}}=\frac{56}{1330}=.042105263[/tex]
NEED ANSWER WITH WORK PLEASEEEEE QUICK !!
Answer:
Step-by-step explanation:
the equation has the form of y = mx + b (slope intercept form)
where m = - 1/5
start with the point-slope form and work it to the slope-intercept form
y-y1 = m(x-x1) (point-slope form)
y-5 = -1/5(x-(-5))
y-5 = -1/5(x+5)
y-5 = -1/5(x) + -1/5(5)
y-5 = -x/5 + - 5/5
y-5 = -[tex]\frac{1}{5}[/tex] X -1
y = -[tex]\frac{1}{5}[/tex] X - 1 +5
y = -[tex]\frac{1}{5}[/tex] X +4
there you go :)
the sum of the square of the number and a second number is 42
Step-by-step explanation:
x+x squared =42. The square of the number is the number square. By my incredibly accurate guess and check strategy (works most of the time )6*6 = 36+6=42
Given points A(-1, -2) and B(2, 4) where AP: BP=1:2, find the locus of point P.
Answer:
[tex]x^2 + 4x + y^2 +8y = 0[/tex]
Step-by-step explanation:
Given
[tex]A = (-1,-2)[/tex]
[tex]B = (2,4)[/tex]
[tex]AP:BP = 1 : 2[/tex]
Required
The locus of P
[tex]AP:BP = 1 : 2[/tex]
Express as fraction
[tex]\frac{AP}{BP} = \frac{1}{2}[/tex]
Cross multiply
[tex]2AP = BP[/tex]
Calculate AP and BP using the following distance formula:
[tex]d = \sqrt{(x - x_1)^2 + (y - y_1)^2}[/tex]
So, we have:
[tex]2 * \sqrt{(x - -1)^2 + (y - -2)^2} = \sqrt{(x - 2)^2 + (y - 4)^2}[/tex]
[tex]2 * \sqrt{(x +1)^2 + (y +2)^2} = \sqrt{(x - 2)^2 + (y - 4)^2}[/tex]
Take square of both sides
[tex]4 * [(x +1)^2 + (y +2)^2] = (x - 2)^2 + (y - 4)^2[/tex]
Evaluate all squares
[tex]4 * [x^2 + 2x + 1 + y^2 +4y + 4] = x^2 - 4x + 4 + y^2 - 8y + 16[/tex]
Collect and evaluate like terms
[tex]4 * [x^2 + 2x + y^2 +4y + 5] = x^2 - 4x + y^2 - 8y + 20[/tex]
Open brackets
[tex]4x^2 + 8x + 4y^2 +16y + 20 = x^2 - 4x + y^2 - 8y + 20[/tex]
Collect like terms
[tex]4x^2 - x^2 + 8x + 4x + 4y^2 -y^2 +16y + 8y + 20 - 20 = 0[/tex]
[tex]3x^2 + 12x + 3y^2 +24y = 0[/tex]
Divide through by 3
[tex]x^2 + 4x + y^2 +8y = 0[/tex]
I need help with question 9
9514 1404 393
Answer:
a) yes
b) see attached
c) see discussion
d) neither
e) increasing (2,5); decreasing (-2, 2)
Step-by-step explanation:
a) The graph passes the vertical line test, so is the graph of a function.
__
b) A table of values is attached
__
c) Generally, this sort of function would be defined piecewise:
[tex]\displaystyle f(x)=\begin{cases}-\dfrac{1}{2}x+1&\text{for }-2\le x<2\\2x-4&\text{for }2\le x \le5\end{cases}[/tex]
In the attachment, we have shown the use of the "maximum" function to define it. The effect is the same.
__
d) The function has no symmetry about the origin or the y-axis, so is neither odd nor even.
__
e) The function is increasing where the line has positive slope, on the interval (2, 5). The function is decreasing where the line has negative slope, on the interval (-2, 2).
Ms. Ambrose paid $10 for 1.25 pounds of almonds. How much did the almonds cost per pound???
.What is the value of x if 2(x+1) = 16 ?
2(x +1) = 16
Use the distributive property ( multiply 2 by each term inside the parenthesis).
2x + 2 = 16
Subtract 2 from both sides:
2x = 14
Divide both sides by 2:
x = 7
Answer:
7
Step-by-step explanation:
2x+2=16
2x=16-2
x=16-2/2
x=14/2=7
[tex]z^{7}=128i[/tex]
z = ____ + ____ i
If z ⁷ = 128i, then there are 7 complex numbers z that satisfy this equation.
[tex]z^7 = 128i = 2^7i = 2^7e^{i\frac\pi2}[/tex]
[tex]\implies z=\sqrt[7]{2^7} e^{i\frac17\left(\frac\pi2+2n\pi\right)}[/tex]
(where n = 0, 1, 2, …, 6)
[tex]\implies z = 2 e^{i\left(\frac\pi{14}+\frac{2n\pi}7\right)}[/tex]
[tex]\displaystyle\implies z = 2 \left(\cos\left(\frac\pi{14}+\frac{2n\pi}7\right)+i\sin\left(\frac\pi{14}+\frac{2n\pi}7\right)\right)[/tex]
Consider the exponential function f(x) = One-fifth(15x). What is the value of the growth factor of the function?
Answer:
15
Step-by-step explanation:
PLEASE BE RIGHT AND SOLVE
Answer:
Option B: Rotation
Step-by-step explanation:
The shape appears to have the same size, but it has been moved in a way that is not reflection. Through the process of elimination, the answer is rotation.
Robert paid $4.5 for 3 apples. Find the cost per apple.
Answer:
$1.50
Step-by-step explanation:
so its
4.5 ÷ 3
which
1.5
Identify the level of measurement of the data, and explain what is wrong with the given calculation. Ina set of data, alert levels are represented as 1 for low, 2 for medium, and 3 for high. The average mean of the 522 alert levels is 1.3. The data are at the ________ level of measurement. a. Nominalb. Ordinalc. Ratiod. IntervalWhat is wrong with the given calculation?a. Such data should not be used for calculations such as an average.b. One must use a different method to take the average of such datac. The true average is 2.5d. There is nothing wrong with the given calculation.
Answer:
(1) Ordinal
(2) Such data should not be used for calculations such as an average.
Step-by-step explanation:
Given
[tex]1 \to Low[/tex]
[tex]2 \to Medium[/tex]
[tex]3 \to High[/tex]
[tex]Average = 1.3[/tex]
Solving (a): The level of measurement
When observations are presented in ranks such as:
[tex]1 \to Low[/tex]
[tex]2 \to Medium[/tex]
[tex]3 \to High[/tex]
The level of measurement of such observation is ordinal
Solving (b): What is wrong with the computation?
Ordinal level of measurement are not numerical values whose average can be calculated because they are used as ranks.
Hence, (a) is correct
Write the formula of the function y whose graph is shown.
Answer:
This looks like the graph of [tex]f(x)=\frac{1}{x}[/tex] ! That's a reciprocal graph.
(3b-4)(b+2) in standard form
Answer:
3b^2 + 2b -8
Step-by-step explanation:
* means multiply
^ means exponent
3b * b = 3b^2
3b * 2 = 6b
-4 * b = -4b
-4 * 2 = -8
3b^2 + 6b -4b -8
3b^2 + 2b -8
What is the absolute value of -20?
there was a number line so
——————————————
-20 -10 0 10 20
and the options were
A.) -20
B.) 0
C.) 20
D.) 40
Answer:
C) 20
Step-by-step explanation:
The absolute value of a number represents the positive distance between the number and zero. Absolute value is therefore always positive.
The distance between -20 and 0 is 20 and therefore the answer is C) 20.
Answer:
20
Step-by-step explanation:
Absolute value = | -20 |
= 20
Option C is correct .