According to a Pew Research Center study, in May 2011, 40% of all American adults had a smart phone (one which the user can use to read email and surf the Internet). A communications professor at a university believes this percentage is higher among community college students. She selects 341 community college students at random and finds that 147 of them have a smart phone. Then in testing the hypotheses:

H0: p = 0.4 versus

Ha: p > 0.4,

what is the test statistic?

z =________________. (Please round your answer to two decimal places.)

B.)

According to a Pew Research Center study, in May 2011, 33% of all American adults had a smart phone (one which the user can use to read email and surf the Internet). A communications professor at a university believes this percentage is higher among community college students. She selects 349 community college students at random and finds that 138 of them have a smart phone. In testing the hypotheses:

H0: p = 0.33 versus

Ha: p > 0.33,

she calculates the test statistic as z = 2.5990.

Then the p‑value =________________ .

(Please round your answer to four decimal places.)

Answer:

a)

H₀ : µd = 0  

H₁ : µd < 0  

b)

The test statistic is

tₙ₋₁ = α / s√n

c)

at 0.10 level of significance,

tₙ₋₁ , ₐ

t₃₀₋₁ , ₀.₁₀ = t₂₉, ₀.₁₀ = 1.311

d)

given that  T(critical) = 1.62

∴ T(critical) = 1.62 > t₂₉, ₀.₁₀ = 1.311

at 10% level of significance,

REJECT H₀

Since 1.62 > 1.311, we can reject the null hypothesis.

Answer:

1 +3i

Step-by-step explanation:

(4 - 2i) - (3 - 5i)

Subtract the reals

4 - 3 =1

Subtract the imaginary

-2i - -5i

-2i + 5i = 3i

1 +3i

Answer:

A

Step-by-step explanation:

Subtract all real numbers

4 - 3 = 1

Subtract all imaginary numbers

-2i - (-5i) = 3i

Put back together

1 + 3i

Best of Luck!

Answer:

252

Step-by-step explanation:

Divide 7812 by 31 and we get the average daily answer... Hope this helps!!

Answer:

157

Step-by-step explanation:

135+144+116+132=527

527+136.8=762.8

762.8÷5= 157

Answer:

2.83

Step-by-step explanation:

For a normally distributed data :

Mean = 3.1 inches

Standard deviation = 0.4 inches

Find the value of the quartile Q1:

The quartile Q1 represents the first quartile which is the Lower 25% of the distribution

25% = 0.25

Using the z-table :

0.25 = - 0.68

The z- score formula

Z-score = ( x - mean / standard deviation)

-0.68 = ((x - 3.1) / 0.4)

x - 3.1 = (-0.68 * 0.4)

x - 3.1 = - 0.272

x = - 0.272 + 3.1

x = 2.828

x = 2.83

Answer:

  log(1/10) = -1

Step-by-step explanation:

Use the law of exponents and the meaning of logarithm.

  1/10 = 10^-1

  log(10^x) = x

So, you have ...

  log(1/10) = log(10^-1)

  log(1/10) = -1

Answer: 0.9844

Step-by-step explanation:

given data:

sample size n = 6

It’s assumed that half the population are male and the remaining half are females

F = 1/2

M = 1/2

the probability that the investigator would draw altleats one male

P ( x ≥ 1 ) =

= 1 - ( 0.5 ) ^ 6

= ( 0.5 )^6

= 0.9844

Answer:

(1) Therefore, a 90% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it is [0.4348, 0.5252].

(2) We can be 90% confident that the proportion of Americans who choose not to go to college because they cannot afford it is contained within our confidence interval

(3) A survey should include at least 3002 people if we wanted the margin of error for the 90% confidence level to be about 1.5%.

Step-by-step explanation:

We are given that a simple random sample of 331 American adults who do not have a four-year college degree and are not currently enrolled in school, 48% said they decided not to go to college because they could not afford school.

Firstly, the pivotal quantity for finding the confidence interval for the population proportion is given by;

                         P.Q.  =  [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex]  ~ N(0,1)

where, [tex]\hat p[/tex] = sample proportion of Americans who decide to not go to college = 48%

           n = sample of American adults = 331

           p = population proportion of Americans who decide to not go to

                 college because they cannot afford it

Here for constructing a 90% confidence interval we have used a One-sample z-test for proportions.

So, 90% confidence interval for the population proportion, p is ;

P(-1.645 < N(0,1) < 1.645) = 0.90  {As the critical value of z at 5% level

                                                        of significance are -1.645 & 1.645}  

P(-1.645 < [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < 1.645) = 0.90

P( [tex]-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < [tex]\hat p-p[/tex] < [tex]1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.90

P( [tex]\hat p-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < p < [tex]\hat p+1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.90

90% confidence interval for p = [ [tex]\hat p-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] , [tex]\hat p+1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ]

 = [ [tex]0.48 -1.96 \times {\sqrt{\frac{0.48(1-0.48)}{331} } }[/tex] , [tex]0.48 +1.96 \times {\sqrt{\frac{0.48(1-0.48)}{331} } }[/tex] ]

 = [0.4348, 0.5252]

(1) Therefore, a 90% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it is [0.4348, 0.5252].

(2) The interpretation of the above confidence interval is that we can be 90% confident that the proportion of Americans who choose not to go to college because they cannot afford it is contained within our confidence interval.

3) Now, it is given that we wanted the margin of error for the 90% confidence level to be about 1.5%.

So, the margin of error =  [tex]Z_(_\frac{\alpha}{2}_) \times \sqrt{\frac{\hat p(1-\hat p)}{n} }[/tex]

              [tex]0.015 = 1.645 \times \sqrt{\frac{0.48(1-0.48)}{n} }[/tex]

              [tex]\sqrt{n} = \frac{1.645 \times \sqrt{0.48 \times 0.52} }{0.015}[/tex]

              [tex]\sqrt{n}[/tex] = 54.79

               n = [tex]54.79^{2}[/tex]

               n = 3001.88 ≈ 3002

Hence, a survey should include at least 3002 people if we wanted the margin of error for the 90% confidence level to be about 1.5%.

Answer:

Step-by-step explanation:

f(x) = (x+1)³ + 4

To find f-¹(x) equate f(x) to y

That's

y = (x+1)³ + 4

Next interchange the terms x becomes y and y becomes x

That's

x = ( y+1)³ + 4

Make y the subject

(y+1)³ = x - 4

Find the cube root of both sides

That's

[tex]y + 1 = \sqrt[3]{x - 4} [/tex]

Send 1 to the right side of the equation

That's

[tex]y = \sqrt[3]{x - 4} - 1[/tex]

So we have the final answer as

[tex]f ^{ - 1} (x) = \sqrt[3]{x - 4} - 1[/tex]

Hope this helps you

Answer:

option 1

Step-by-step explanation:

f(x)=(x+1)³+4

to find the inverse interchange the variable and solve for y

inverse f(x)=(y+1)³+4

x=(y+1)³+4

x-4=(y+1)³

y+1=∛x-4

y=∛x-4 -1

Answer:

  C.  As x → –∞, y → +∞, and as x → +∞, y → +∞

Step-by-step explanation:

The leading coefficient of this even-degree function is positive, so y goes to +∞ when the magnitude of x gets large.

_____

When the function is even degree, its value for large magnitude x heads toward the infinity with the same sign as the leading coefficient.

When the function is odd degree, its value for large magnitude x will head toward the infinity with the sign that matches the product of the sign of x and the sign of the leading coefficient.

Answer:

Attachment 1 : Option A,

Attachment 2 : Option C

Step-by-step explanation:

( 1 ) Here we know that " n " is 6. Now remember if n is odd, the number of petals on the graph will be n. However if n is even, the number of petals on the graph will be 2n.

6 is even, and hence the number of petals will be 2(6) = 12 petals. Solution : 12 petals

( 2 ) To solve such problems we tend to use the equation [tex]z = x + y * i = r(cos\theta +isin\theta)[/tex] where [tex]r = \sqrt{x^2+y^2}[/tex] etc. Here I find it simpler to see each option, and convert each into it's standard complex form. It might seem hard, but it is easy if you know the value of (cos(5π / 3)) etc...

The answer here will be option c, but let's prove it,

cos(5π / 3) = 1 / 2,

sin(5π / 3) = [tex]-\frac{\sqrt{3}}{2}[/tex]

Plugging those values in for " [tex]8\left(\cos \left(\frac{5\pi }{3}\right)+i\sin \left(\frac{5\pi }{3}\right)\right)[/tex] "

[tex]8\left(-\frac{\sqrt{3}i}{2}+\frac{1}{2}\right)[/tex]

= [tex]8\cdot \frac{1}{2}-8\cdot \frac{\sqrt{3}i}{2}[/tex] = [tex]4-4\sqrt{3}i[/tex]

Hence proved that your solution is option c.

Answer:

A) ( -8, -32 )

Step-by-step explanation:

Given function : f (x,y) = 21 - 4x^2 - 16y^2

point p( 1,1,1 ) on surface

Gradient of F

attached below is the detailed solution

Answer:

=6 units squared

Step-by-step explanation:

area=1/2h(a+b)

        =1/2×2(4+2)

        =6

Answer:

(x,y) -> (x+6, y-3)

Step-by-step explanation:

I followed c and it translated like the  last ans choice.

Answer:

1) a) 0.8

b) 0.6

2) a) 0.08

b) 0.14

Step-by-step explanation:

1) Given

[tex]P(A) = 0.3[/tex] and [tex]P(B) = 0.5[/tex]

Let us learn about a formula:

[tex]P(A\ or\ B) = P(A) +P(B) -P(A\ and\ B)\\OR\\P(A\cup B) = P(A) +P(B) -P(A\cap B)[/tex]

(a) If A and B are mutually exclusive i.e. no common thing in the two events.

In other words:

[tex]P(A\ and\ B)[/tex] = [tex]P(A \cap B)[/tex] = 0

Using above formula:

[tex]P(A\ or\ B) = P(A) +P(B) -P(A\ and\ B)\\\Rightarrow P(A\ or\ B) = 0.3 + 0.5 -0 = \bold{0.8}[/tex]

(b)  P(A and B) = 0.2

Using above formula:

[tex]P(A\ or\ B) = P(A) +P(B) -P(A\ and\ B)\\\Rightarrow P(A\ or\ B) = 0.3 + 0.5 -0.2 = \bold{0.6}[/tex]

*************************************

1) Given

[tex]P(A) = 0.4[/tex] and [tex]P(B) = 0.2[/tex]

Let us learn about a formula:

[tex]P(A\ and\ B) = P(B) \times P(A/B)[/tex]  for dependent events

[tex]P(A\ and\ B) = P(A) \times P(B)[/tex] for independent events.

(a) If A and B are independent events :

Using the above formula for independent events:

[tex]P(A\ and\ B) = 0.4 \times 0.2 = \bold{0.08}[/tex]

(b)  [tex]P(A / B) = 0.7[/tex]

Using above formula:

[tex]P(A\ and\ B) = P(B) \times P(A/B) = 0.2 \times 0.7 = \bold{0.14}[/tex]

Answer:

The author have to use his/her phone less than 20 hours in a month in order for Don’tTalkMuch's is a deal to be better than TalkLots's is.

Step-by-step explanation:

Call X is the number of hours that the author uses on monthly basis.

Total bill value if the author uses Don’tTalkMuch service is $80 + $1 X.

Total bill value if the author uses TalkLots service is $20 + $4X

The total fees between 2 providers equal as:

$80 + $1 X = $20 + $4X => 3X = $60 => X = 20

Hence: The author have to use his/her phone less than 20 hours in a month in order for Don’tTalkMuch's is a deal to be better than TalkLots's is.

Answer:

15.7% of students made above an 89.

Step-by-step explanation:

If the data is normally distributed, the standard deviation is 7, and the mean is 82, then about 68.2% of students made between 75 and 89. 13.6% made between 90 and 96, and 2.1% made over 96. 13.6+2.1=15.7%

Answer:

Which polynomial is prime?

7x2 – 35x + 2x – 10

9x3 + 11x2 + 3x – 33  

10x3 – 15x2 + 8x – 12  

12x4 + 42x2 + 4x2 + 14

Step-by-step explanation:

Which polynomial is prime?

7x2 – 35x + 2x – 10

9x3 + 11x2 + 3x – 33  

10x3 – 15x2 + 8x – 12  

12x4 + 42x2 + 4x2 + 14 SO IT IS RIGHT

Answer:

45

Step-by-step explanation:

2 digit number starts from 10 ends at 99

between 10 and 19 there is only one number whose tens digit is more than ones digit.

that is 10

between 20 and 29 there are two numbers

20 and 21

like the same

between 30 and 39 there are 3 numbers

10–19. 1

20–29. 2

30–39. 3

40–49. 4

50–59. 5

60–69. 6

70–79. 7

80–89. 8

99–99. 9

sum of first n natural numbers is n(n+1)/2

9(9+1)/2=45

Three numbers between 10 and 99 have tens places that are precisely three times larger than their one's places.

The foundation of our whole number system is place value. In this approach, the value of a digit in a number is determined by where it appears in the number.

The tens digit must be three times larger than the units digit in order to meet the requirement. The units digit can have one of the following values: 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9.

Since we are seeking two-digit integers, it is not possible if the unit digit is zero for the tens digit also be zero.

In the case when the unit digit is 1, the tens digit must be 3, resulting in the number 31. Similar to the previous example, if the unit digit is 2, the tens digit must be 6, resulting in the number 62.

As we proceed, we discover the following integers meet the condition:

31, 62, 93

Therefore, there are three numbers from 10 to 99 that have a tens place exactly 3 times greater than their one's place.

Learn more about place values here:

https://brainly.com/question/27734142

#SPJ3

Step-by-step explanation:

Ellen - 115/23

Classmates and Ellen got = 5 each

Answer:

The dimensions or Area of the rectangle is 1200cm².

Complete Question

A population has a mean mu μ equals = 77 and a standard deviation σ = 14. Find the mean and standard deviation of a sampling distribution of sample means with sample size n equals = 26

Answer:

The mean of sampling distribution of the sample mean ( [tex]\= x[/tex]) is [tex]\mu_{\= x } = 77[/tex]

The standard deviation of sampling distribution of the sample mean ( [tex]\= x[/tex]) is  

    [tex]\sigma _{\= x} = 2.746[/tex]

Step-by-step explanation:

From the question we are told that

    The population mean is  [tex]\mu = 77[/tex]

     The  standard deviation is  [tex]\sigma = 14[/tex]

     The sample size is  [tex]n = 26[/tex]

Generally the standard deviation of sampling distribution of the sample mean ( [tex]\= x[/tex]) is  mathematically represented as

           [tex]\sigma _{\= x} = \frac{ \sigma }{ \sqrt{n} }[/tex]

substituting values  

          [tex]\sigma _{\= x} = \frac{ 14}{ \sqrt{26} }[/tex]

          [tex]\sigma _{\= x} = 2.746[/tex]

Generally the mean of sampling distribution of the sample mean ( [tex]\= x[/tex]) is  equivalent to the population mean i.e  

      [tex]\mu_{\= x } = \mu[/tex]

      [tex]\mu_{\= x } = 77[/tex]

Answer:

its multiple choice

A. 26inches (1inch/25.4mm)

B. 26inches (25.4mm/1inch)

C. 25.4inches (1mm/26inch)

D. 26inches (1mm/25.4inch)

and its b

Answer:

x = 6

Step-by-step explanation:

In the third line of the solution on right side of the equal sign, middle term should be 8x instead of 4x.

The final value of x will be 6.

[tex] PQ^2 + QO^2 = PO^2 \\

x^2 + 8^2 = (4+x)^2 \\

x^2 + 64 = 16 + 8x + x^2 \\

64 = 16 + 8x \\

64 - 16 = 8x \\

48 = 8x \\

6 = x\\[/tex]

Answer:

2.8

Step-by-step explanation:

11.1-8.3=2.8

HOPE I HELPED

PLS MARK BRAINLIEST

DESPERATELY TRYING TO LEVEL UP

✌ -ZYLYNN JADE ARDENNE

JUST A RANDOM GIRL WANTING TO HELP PEOPLE!

                            PEACE!

x = liters of 1% solution

y = liters of 5% solution

x + y = 16

0.01x + 0.05y = 0.04*16 = 0.64

y = 16 - x

0.01x + 0.05(16 - x) = 0.64

0.01x + 0.8 - 0.05x = 0.64

0.16 = 0.04x

x = 4

y = 12

Answer:

27.73 feet

Step-by-step explanation:

Use the Pythagorean theorem. It easiest to think of the distance between the two friends as a triangle in the rectangle. One side is 12ft and the other is 25ft.

12^2+25ft^2=769

The square root of 769 is 27.73

Answer:

27.73 Ft

Step-by-step explanation:I took the test

Answer:

a. 7k - 7

Step-by-step explanation:

Step 1: Write out expression

-k - (-8k + 7)

Step 2: Distribute negative

-k + 8k - 7

Step 3: Combine like terms

7k - 7

And we have our answer!