4. The average annual income of 100 randomly chosen residents of Santa Cruz is $30,755 with a standard deviation of $20,450. a) What is the standard deviation of the annual income? b) Test the hypothesis that the average annual income is $32,000 against the alternative that it is less than $32,000 at the 10% level. c) Test the hypothesis that the average annual income is equal to $33,000 against the alternative that it is not at the 5% level. d) What is the 95% confidence interval of the average annual income?

Answer:

[tex]cos(-\theta) = -0.73[/tex]

Step-by-step explanation:

It is given that:

[tex]sin(\theta -\dfrac{\pi}{2}) = 0.73[/tex]

Formula to be used:

[tex]1.\ sin(-x) = -sinx\\2.\ sin(\dfrac{\pi}{2}-x) = cosx\\3.\ cos(-x) = cosx[/tex]

Using Formula (1) written above:

[tex]\Rightarrow sin (\theta - \dfrac{\pi}{2})=sin(-(\dfrac{\pi}{2}-\theta ))\\\Rightarrow -sin(\dfrac{\pi}{2}-\theta)[/tex]

Now, using Formula (2) written above:

[tex]\Rightarrow -sin(\dfrac{\pi}{2}-\theta) = -cos \theta[/tex]

So, we can say that:

[tex]sin(\theta -\dfrac{\pi}{2}) = -cos\theta = 0.73 ...... (1)[/tex]

We have to find the value of [tex]cos(-\theta)[/tex].

Using Formula (3) written above:

[tex]cos(-\theta) = cos\theta[/tex]

So, ultimately we need to find the value of [tex]cos\theta[/tex]

Using equation (1):

[tex]-cos\theta = 0.73\\\Rightarrow cos\theta = -0.73[/tex]

So, the answer is [tex]cos(-\theta) = -0.73[/tex].

Answer:

11.24

Step-by-step explanation:

If she arrived at 12.15, to find the time of departure we have to deduct 33 mins and the time she spent for photos,18 mins from this to get time of departure.

Total time spent for journey

33mins +18 mins = 51mins

time of departure = 12.15 - 51mins

so the time of departure is 11.24

Answer:

D not sure if its right tho

Answer:6

Step-by-step explanation:

Green

x=14.7

y=8.5

Red

x=3.5

y=6

Answer:

The Probability that will pick a red tile from the bag

[tex]P(E) = \frac{6}{11}[/tex] = 0.545

Step-by-step explanation:

Explanation:-

Given data 4 blue tiles, 12 red tiles, and 6 green tiles in a bag

Total = 4 B + 12 R + 6 G = 22 tiles

Total number of exhaustive cases

         n (S) = [tex]22 C_{1} = 22 ways[/tex]

The Probability that will pick a red tile from the bag

[tex]P(E) = \frac{n(E)}{n(S)} = \frac{12 C_{1} }{22 C_{1} } = \frac{12}{22}[/tex]

[tex]P(E) = \frac{6}{11}[/tex]

P(E) = 0.545

Final answer:-

The Probability that will pick a red tile from the bag = 0.545

Answer:  The answer has one solution:

_______________________________

      →  x = 1 ;   y =  -4 ;  or, write as:  [1, -4].

_______________________________

Step-by-step explanation:

_______________________________

Given:

  y  =  - 1x – 3

  y  =   -7x + 3 ;

_______________________________

    -1x – 3  =   -7x + 3  ;  Solve for "x" ;

Add:  " +1x" ; and add " +3 " ;  to Each Side of the equation:

Subtract " 1x " ; and Subtract " 1 " ; from Each Side of the equation:

   -1x  + 1x  – 3  + 3  =  -7x  + 1x + 3 + 3 ;

         to get:  

             0  =  -6x + 6

          ↔  -6x + 6 = 0 ;

Now, subtract " 6 " from Each Side of the equation:

                -6x + 6 – 6  = 0 – 6  ;

       to get:

               -6x = -6 ;

Now, divide Each Side of the equation by " -6 ";  

      to isolate "x" on one side of the equation;

      & to solve for "x" ;

              -6x /-6  =  -6/-6 ;

      to get:

                x = 1 .

_______________________________

Now, let us solve for "y" ;  

We are given:  

 y =  -x – 3  ;

Substitute our solved value for "x" ; which is:  " 1 " ; for " x " ; into this given equation; to obtain the value for " y " :

 y =  -x – 3  ;

    =  -1  – 3  

 y =   - 4 .

_______________________________

Let us check our answers by plugging the values for "x" and "y" ;

" 1 " ; and " -4 "; respectively);  into the second given equation; to see if these values for " x " and " y"  ; hold true:

Given:   y  =    - 7x  +  3 ;

           →  -4   =?  -7(1) + 3 ??  ;

           →  -4   =?   -7   + 3  ??  ;

           →  - 4 =?   -4 ?? ;

           →  Yes!

_______________________________

The answer has one solution:

      →  x = 1 ;   y =  - 4 ;  or, write as:  [1, -4 ].

_______________________________

Hope this is helpful!  Best wishes!

_______________________________

Answer:

The probability that exactly eight of them take more than 93.6 minutes is 5.6015 [tex]\times 10^{-6}[/tex] .

Step-by-step explanation:

We are given that it is known that times for service calls follow a normal distribution with a mean of 75 minutes and a standard deviation of 15 minutes.

A random sample of twelve service calls is taken.

So, firstly we will find the probability that service calls take more than 93.6 minutes.

Let X = times for service calls.

So, X ~ Normal([tex]\mu=75,\sigma^{2} =15^{2}[/tex])

The z-score probability distribution for the normal distribution is given by;

                              Z  =  [tex]\frac{X-\mu}{\sigma}[/tex]  ~ N(0,1)

where, [tex]\mu[/tex] = mean time = 75 minutes

           [tex]\sigma[/tex] = standard deviation = 15 minutes

Now, the probability that service calls take more than 93.6 minutes is given by = P(X > 93.6 minutes)

       P(X > 93.6 min) = P( [tex]\frac{X-\mu}{\sigma}[/tex] > [tex]\frac{93.6-75}{15}[/tex] ) = P(Z > 1.24) = 1 - P(Z [tex]\leq[/tex] 1.24)

                                                                = 1 - 0.8925 = 0.1075

The above probability is calculated by looking at the value of x = 1.24 in the z table which has an area of 0.8925.

Now, we will use the binomial distribution to find the probability that exactly eight of them take more than 93.6 minutes, that is;

[tex]P(Y = y) = \binom{n}{r}\times p^{r} \times (1-p)^{n-r} ; y = 0,1,2,3,.........[/tex]

where, n = number of trials (samples) taken = 12 service calls

            r = number of success = exactly 8

            p = probability of success which in our question is probability that

                   it takes more than 93.6 minutes, i.e. p = 0.1075.

Let Y = Number of service calls which takes more than 93.6 minutes

So, Y ~ Binom(n = 12, p = 0.1075)

Now, the probability that exactly eight of them take more than 93.6 minutes is given by = P(Y = 8)

               P(Y = 8)  =  [tex]\binom{12}{8}\times 0.1075^{8} \times (1-0.1075)^{12-8}[/tex]

                             =  [tex]495 \times 0.1075^{8} \times 0.8925^{4}[/tex]

                             =  5.6015 [tex]\times 10^{-6}[/tex] .

Answer:

0.5 or C on edge2021

Step-by-step explanation:

The multiplicative rate of change of the function will be:

The multiplicative rate of change is the common factor that the numbers can be multiplied with to get the succeeding figures.

For instance, if 0.25 is multiplied by 0.5, the result will be 0.125. Also, if 0.125 is multiplied by 0.5, the result will be 0.0625.

Learn more about the multiplicative rate of change here:

https://brainly.com/question/4319809

#SPJ9

Answer:

[tex] \bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})[/tex]

And replacing:

[tex] \mu_{\bar X}= 5[/tex]

And the deviation:

[tex] \sigma_{\bar X}= \frac{0.283}{\sqrt{5}}= 0.126[/tex]

And the distribution is given:

[tex] \bar X \sim N(\mu= 0.08, \sigma= 0.126)[/tex]

Step-by-step explanation:

For this case we have the following info given :

[tex] \mu= 5. \sigma^2 =0.08[/tex]

And the deviation would be [tex] \sigma = \sqrt{0.08}= 0.283[/tex]

For this case we select a sample size of n = 5 and the distirbution for the sample mean would be:

[tex] \bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})[/tex]

And replacing:

[tex] \mu_{\bar X}= 5[/tex]

And the deviation:

[tex] \sigma_{\bar X}= \frac{0.283}{\sqrt{5}}= 0.126[/tex]

And the distribution is given:

[tex] \bar X \sim N(\mu= 0.08, \sigma= 0.126)[/tex]

Answer: scalene and right

Step-by-step explanation:

Answer:

(a) -2,0 and 2,5 and (b) 2,-1 and 10,9

Question:

The question is incomplete without the answer choice. Let's consider the following:

A line has a slope of -4/5. Which ordered pairs could be points on a line that is perpendicular to this line? select two options

a) -2,0 and 2,5

b) -4,5 and 4,-5

c) -3,4 and 2,0

d) 1,-1 and 6,-5

e) 2,-1 and 10,9

Step-by-step explanation:

The ordered pairs that could be points on a line that is perpendicular to this line would have same slope as that of the line.

Let's check out the slope of the options.

The line has slope = -4/5

Slope = m = (y subscript 2 -y subscript 1)/(x subscript 2 - x subscript 1)

The coordinates is in the form of (x,y)

Find attached the workings.

a) -2,0 and 2,5

m = 5/4

b) -4,5 and 4,-5

m = -5/4

c) -3,4 and 2,0

m = -4/5

d) 1,-1 and 6,-5

m = -4/5

e) 2,-1 and 10,9

m = 5/4

Two lines are perpendicular if (m subscript 1) × (m subscript 2) = -1

In other words, the slopes

of the two lines must be negative reciprocals of each other.

If 1st slope = -4/5

For the lines to be perpendicular, the slope of every other line = 5/4

2nd slope = 5/4

The ordered pairs that are points on the line perpendicular to the line:

(a) -2,0 and 2,5 and (b) 2,-1 and 10,9

Answer:AandE

Step-by-step explanation:

Answer:

3724 in^3

Step-by-step explanation:

19 times 14 times 14 = 3724

Answer:

3724 inches ³

Step-by-step explanation:

Volume of cooler = whl

Where w is width, h is height and l is length

V = (19)(14)(14)

V = 3724 inches³

Answer:

A . 0.85 + (0.15 +(-3)) = -2

B . [(-3)+(-3)]+(-3) = - 9

Step-by-step explanation:

Explanation:-

Associative  property with addition

(a+(b+c)) = (a+b) + c

A)

Given 0.85 + (0.15 +(-3)) = (0.85 +0.15)+(-3)

                                       = 1 - 3

                                       = -2

B)  Given [(-3)+(-3)]+(-3) = ( (-3)+[( -3)+(-3))]

                                     = ( -3 +[-3-3]

                                    =  -3 -6

                                    = -9

Final answer:-

A . 0.85 + (0.15 +(-3)) = -2

B . [(-3)+(-3)]+(-3) = - 9

Answer:

The range of the random variable is {0, 1, 2}.

Step-by-step explanation:

The bag contains red and blue marbles.

The experiments consists of two draws, with reposition.

The random variable assigns the number of blue  marbles to each outcome.

If we have only two draws, we can only get 0, 1 or 2 blue marbles.

The range of the random variable is {0, 1, 2}.

Answer:

The first one matches with f(x)√x because a square root cannot be negative

The second one matches with f(x)=√(x-5) because the square root would be negative if it were less than five.

The third one matches with f(x)=8x because there is nothing that makes it a not possible answer

The last one matches with 7/(x-8) because there cannot be a denominator of zero.

Answer:

1/2

Step-by-step explanation:

Find two points on the line

(2,0) and (4,1)

The slope is given by

m= (y2-y1)/(x2-x1)

   =(1-0)/(4-2)

   = 1/2

Answer:

a) 38

Step-by-step explanation:

The normal distribution can be applied if:

[tex]np \geq 5[/tex] and [tex]n(1-p) \geq 5[/tex]

In this question:

[tex]p = 0.27[/tex]

Then

a) 38

n = 38.

Then

38*0.27 = 10.26

38*0.73 = 27.74

Satisfies. But is this the smallest sample of the options which satisfies.

b) 14

n = 14

Then

14*0.23 = 3.22

14*0.77 = 10.78

Does not satisfy

c) 10

Smaller than 14, which also does not satisfy, so 10 does not satisfy.

d) 48

Greater than 38, which already satisfies. So the answer is a)

Answer:

The one with the better deal would be 30 ride tickets for $22.50 this is because you pay less money for more rides.

Step-by-step explanation:

First you divide 20 by 14. Doing this will give you the cost of a ride per ticket.

20/14 = 1.42

Then you do the same thing to 30 and 22.50.

30/22.50 = 1.30

Last you compare which deal has less money per ride.

1.42 > 1.30

Answer:

0.347% of the total tires will be rejected as underweight.

Step-by-step explanation:

For a standard normal distribution, (with mean 0 and standard deviation 1), the lower and upper quartiles are located at -0.67448 and +0.67448 respectively. Thus the interquartile range (IQR) is 1.34896.

And the manager decides to reject a tire as underweight if it falls more than 1.5 interquartile ranges below the lower quartile of the specified shipment of tires.

1.5 of the Interquartile range = 1.5 × 1.34896 = 2.02344

1.5 of the interquartile range below the lower quartile = (lower quartile) - (1.5 of Interquartile range) = -0.67448 - 2.02344 = -2.69792

The proportion of tires that will fall 1.5 of the interquartile range below the lower quartile = P(x < -2.69792) ≈ P(x < -2.70)

Using data from the normal distribution table

P(x < -2.70) = 0.00347 = 0.347% of the total tires will be rejected as underweight

Hope this Helps!!!

The proportion of the tires that would be denied for being underweight through the given process would be:

[tex]0.347[/tex]% of the total tires will be rejected as underweight.

Given that,

Interquartile Range [tex]= 1.5[/tex]

Standard Deviation [tex]= 0.76[/tex]

Considering Mean = 0

and Standard Deviation = 1

Since lower quartile = -0.67448

Upper quartile  = +0.67448

IQ range =  1.34896

To find,

The proportion of tires would be rejected due to being underweight through the process would be:  

1.5 of Interquartile Range = 1.5 × [tex]1.34896 = 2.02344[/tex]

Now,

1.5 of the IQ range below the lower quartile [tex]= (lower quartile) - (1.5 of Interquartile range)[/tex]

[tex]= -0.67448 - 2.02344[/tex]

[tex]= -2.69792[/tex]

The proportion of tires that would be under 1.5 of the interquartile range below the lower quartile:

[tex]= P(x < -2.69792)[/tex] ≈ [tex]P(x < -2.70)[/tex]

Using data through the Normal Distribution Table,

[tex]P(x < -2.70)[/tex] [tex]= 0.00347[/tex]

[tex]= 0.347[/tex]%

Thus, 0.347% of the total tires would be rejected as underweight.

Learn more about "Proportion" here:

brainly.com/question/2548537

Answer:

The length of the diameter of this circular area is of 30 miles.

Step-by-step explanation:

The area of a circular region can be represented by the following equation:

[tex]A = \pi r^{2}[/tex]

In which r is the radius. The diameter is twice the radius.

In this question:

[tex]A = 225\pi[/tex]

So

[tex]A = \pi r^{2}[/tex]

[tex]225\pi = \pi r^{2}[/tex]

[tex]r^{2} = 225[/tex]

[tex]r = \pm \sqrt{225}[/tex]

The radius is a positive measure, so

[tex]r = 15[/tex]

Area in squared miles, so the radius in miles.

What is the approximate length of the diameter of this circular area

D = 2r = 2*15 = 30 miles

The length of the diameter of this circular area is of 30 miles.

Answer:

DIDNT UNDERSTAND THE QUESTION PROPERLY BRO..

KEEP THE QUESTION AGAIN

Answer: (b) 15.07 to 19.93 miles

Step-by-step explanation:

Confidence interval is written in the form,

(Sample mean - margin of error, sample mean + margin of error)

The sample mean, x is the point estimate for the population mean.

Margin of error = z × s/√n

Where

s = sample standard deviation = 3.8

n = number of samples = 20

From the information given, the population standard deviation is unknown and the sample size is small, hence, we would use the t distribution to find the z score

In order to use the t distribution, we would determine the degree of freedom, df for the sample.

df = n - 1 = 20 - 1 = 19

Since confidence level = 99% = 0.99, α = 1 - CL = 1 – 0.99 = 0.01

α/2 = 0.02/2 = 0.005

the area to the right of z0.005 is 0.025 and the area to the left of z0.025 is 1 - 0.005 = 0.995

Looking at the t distribution table,

z = 2.861

Margin of error = 2.861 × 3.8/√20

= 2.43

the lower limit of this confidence interval is

17.5 - 2.43 = 15.07 miles

the upper limit of this confidence interval is

17.5 + 2.43 = 19.93 miles

Answer:

The inter-decile range of IQ is 40.96.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 100, \sigma = 16[/tex]

First decile:

100/10 = 10th percentile, which is X when Z has a pvalue of 0.1. So it is X when Z = -1.28.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.28 = \frac{X - 100}{16}[/tex]

[tex]X - 100 = -1.28*16[/tex]

[tex]X = 79.52[/tex]

Ninth decile:

9*(100/10) = 90th percentile, which is X when Z has a pvalue of 0.9. So it is X when Z = 1.28.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.28 = \frac{X - 100}{16}[/tex]

[tex]X - 100 = 1.28*16[/tex]

[tex]X = 120.48[/tex]

Interdecile range:

120.48 - 79.52 = 40.96

The inter-decile range of IQ is 40.96.

Answer:

There are 210 ways

Step-by-step explanation:

The number of ways or combinations in which we can select x elements from a group of n elements where the order doesn't matter can be calculated as:

[tex]nCx=\frac{n!}{x!(n-x)!}[/tex]

So, we have 10 teaching assistants and we need to choose 4 (one assistant per question) to grade each question. It means that n is equal to 10 and x is equal to 4.

Therefore, the number of ways that the assistants can be chosen to grade the exam are calculated as:

[tex]10C4=\frac{10!}{4!(10-4)!}=210[/tex]

Answer:

c.(x+1)^2=10

Step-by-step explanation:

Completing the square:

We use the following relation:

[tex](x + a)^{2} = x^{2} + 2ax + a^{2}[/tex]

In this question:

[tex](x + a)^{2} = x^{2} + 2ax + a^{2} = x^{2} + 2x + a^{2}[/tex]

We have to find a.

[tex]2a = 2[/tex]

[tex]a = \frac{2}{2}[/tex]

[tex]a = 1[/tex]

[tex]x^{2} + 2x + 1 = (x+1)^{2}[/tex]

Thus, we have to add 1 on the right side of the equality.

We end up with:

[tex](x+1)^{2} = 9 + 1[/tex]

[tex](x+1)^{2} = 10[/tex]

So the correct answer is:

c.(x+1)^2=10

Answer:

3.29 s

Step-by-step explanation:

We are given that

Height of building=240

Initial velocity=20ft/s

The height of the ball  after t seconds is given by

[tex]h(t)=-16t^2-20t+240[/tex]

When the ball strike the ground then

h(t)=0

[tex]-16t^2-20t+240=0[/tex]

[tex]4t^2+5t-60=0[/tex]

Quadratic formula:

[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]

Using the quadratic formula

[tex]t=\frac{-5\pm\sqrt{25+960}}{8}[/tex]

[tex]t=\frac{-5\pm\sqrt{985}}{8}[/tex]

[tex]t=\frac{-5+31.28}{8}=3.29 s[/tex]

[tex]t=\frac{-5-31.38}{8}=-4.5[/tex]

Time cannot be negative .Therefore,

t=3.29 s

Answer: 360 cubic centimeters.

Step-by-step explanation:

Since it  has a base shaped like a square and we know that it has a side length of 6 cm then we could square it an multiply it by the height.

6^2 = 36  

36 * 10 = 360

Answer:

[tex]y=50x+75[/tex]

Step-by-step explanation:

When writing a linear equation from a graph, we need to find two things: the y-intercept (what y is when x is 0) and the slope.

First, let us find the y-intercept.

To do this, we can just look at the graph. When x=0, y=75, so 75 is our y-intercept, which is also known as b.

To find the slope of this line, we will need to look at two points

We already know that (0,75) is a point. From the graph, we can see that (1,125) is also a point on this line.

Now, we can find the slope of this line using the following formula [tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]

[tex]m=\frac{125-75}{1-0} \\\\m=\frac{50}{1} \\\\m=50[/tex]

Now that we have both the y-intercept and slope, we can put them together in the form of [tex]y=mx+b[/tex]

[tex]y=50x+75[/tex]

Answer:

Slope: 50

Equation: y = 50x + 75

Step-by-step explanation:

Take two points:

(2,175)

(3,225)

Find the slope:

225 - 175/3 - 2

50/1 = 50

So we get this equation:

y = 50x + b

Now to find b, insert one of those points from before back in:

175 = 50(2) + b

175 = 100 + b

b = 75

So the equation is:

y = 50x + 75

Answer:

Step-by-step explanation:

               x^2

           --------------------------------------------------

2x + 1  /  2x^3     -     x^2    +      x      +    1

               2x^3    +    x^2

              -----------------------

                                    0 + x + 1

                                        x + 1

The quotient is  x^2 + ------------

                                       2x + 1

Answer:

maybe is a

Step-by-step explanation:

Answer:

F(x) = 0.0027x^3 - 21X - 11,430

Step-by-step explanation: