We intend to estimate the average driving time of a group of commuters. From a previous study, we believe that the average time is 42 minutes with a standard deviation of 10 minutes. We want our 90 percent confidence interval to have a margin of error of no more than plus or minus 2 minutes. What is the smallest sample size that we should consider

Answers

Answer 1

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.


Related Questions

Tell whether b=6 is a solution of 8b=48

Answers

Answer:

b= 6 for sure

Step-by-step explanation:

PLS ANSWER QUICK, HELP AND EXPLAIN

Answers

Answer:

136 ft²

Step-by-step explanation:

floor = 7 x 6 = 42 ft²

sides = 2 x 7 x 5 = 70 ft²

ends = 1/2 x 6 x 4 x 2 = 24 ft²

42 + 70 + 24 = 136 ft²

2.8332 rounded to the nearest thousand

Answers

That will be 2.8. Hope this helps

Find the common ratio of the geometric sequence –4, 12, -36,...

Answers

Answer: -3

Step-by-step explanation:

The common ratio of the geometric sequence –4, 12, -36,... is -3.

12/(-4) =-3

-36/(12) = -3

They both multiply -3 for the next number.

7x+1=3x+9 basic equations

Answers

Answer:

= 2

Step-by-step explanation:

Answer:27

Step-by-step explanation:

PLZ HELP ASAP 50 PTS (MATH) + Brainliest

1) Factor the trinomial. Show ALL work:
x2 − 5x + 6

2) Factor the polynomial using grouping. Show ALL work:
5x3-2x2+25x-10


3( Determine the missing term from the perfect square trinomial. Show ALL work.
x2 − ______+ 36
Write in factored form: ( )2

4( Choose ONE of the following polynomial and factor completely, showing ALL work.
16x2 − 81
15x2 − 35
3x2 + 21x + 36

Answers

Answer:

x+3 and x+2( 5 x + 2 ) ( x 2 + 5 )9x^2+163x2 + 21x + 36

Step-by-step explanation:

x2 + 5x + 6

Let us try factorizing this polynomial using splitting the middle term method.

Factoring polynomials by splitting the middle term:

We need to find two numbers ‘a’ and ‘b’ such that a + b =5 and ab = 6.

On solving this we obtain, a = 3 and b = 2

Thus, the above expression can be written as:

x2 + 5x + 6

= x2 + 3x + 2x + 6

= x(x + 3) + 2(x + 3)

= (x + 3)(x + 2)

Thus, x+3 and x+2 are the factors of the polynomial x2 + 5x + 6.

For Step 1, you just want to find all combinations of two numbers that multiply together to be 56. Make sure you take negatives into account. Those pairs of numbers are:

 

(p, q, p+q)

(1, 56, 57)

(-1, -56, -57)

(2, 28, 30)

(-2, -28, -30)

(4, 14, 18)

(-4, -14, -18)

(7, 8, 15)

(-7, -8, -15)

 

Use those pairs of numbers and their sums to fill in the three columns of your table.

STEP 2   Look down your p+q column to find the pair of numbers that add up to equal to -15. That's (p, q) = (-7, -8).   STEP 3   Using the information from steps 1 and 2, you can factor the trinomial like this:   x2 - 15x + 56 = (x + p)(x + q) = (x - 7)(x - 8)   FOIL that back out if you'd like, to make sure the expressions are equivalent.  STEP 4   Hopefully, seeing steps 1 through 3 worked out will help you with step 4. Find all the pairs of numbers that multiply together to be 36 (1 and 36, 2 and 18, 3 and 12, 4 and 9, 6 and 6, and all their negative equivalents), then figure out which pair has a sum of 12. That means you've found your p and q, and can factor the trinomial as (x + p)(x + q).

Answer:

1) Factor the trinomial. Show ALL work:

(x-2)(x-3) steps see explanation

2) Factor the polynomial using grouping.

Group and factor out the greatest common factor (GCF), then combine.

[tex](5x-2) (x^{2} +5)[/tex]

4) Choose ONE of the following polynomial and factor completely.

15x2 − 35 = [tex]5 (3x^2-7)[/tex]

Step-by-step explanation:

x2−5x+6

The middle number is -5 and the last number is 6.

Factoring means we want something like

(x+_)(x+_)

We need two numbers that

Add together to get -5

Multiply together to get 6

Try -2 and -3:

-2+-3 = -5

-2*-3 = 6

Fill in the blanks in

(x+_)(x+_)

with -2 and -3 to get...

(x-2)(x-3)

4( Choose ONE of the following polynomial and factor completely,

15x^2-35

35 as 5*7

15 as 5*3

= 5*3x^2-5*7

Cell phone Plan A costs$70 per month and comes with a free$500 phone. Cell phone Plan Bcosts$50 per month but does not come with a phone. If you buy the$500 phone and choose Plan B, how many months is it until your cost is the same as Plan A's?
Please answer WITHEXPLANATION!

Answers

Answer:

25

Step-by-step explanation:

A = 70*M

B = 500 + 50*M

Costing the same means equal, so we have the equation:

70M = 500 + 50M

-50M           -50M

 

20M = 500

20M / 20 = 500 / 20

m- 25 months

Multiply (2-5i)(2+5i)

Answers

Answer:

29

Step-by-step explanation:

4 - 25i^2

4 - 25x(-1)

4 + 25 = 29

the ^2 means exponent 2

Consider the functions f(x) = x2 - 4x and
g(x) = (x - 2)2 + 3.
Which of the following statements are true? Select all that apply.

A)The graphs of f(x) and g(x) share the same axis of symmetry.

B)The graphs of f (x) and g(x) share the same y-intercept.

C)The graphs of f(x) and g(x) share the same
x-intercepts.

D)The graph of f(x) and g(x) open in the same direction.
The graph of f(x) is wider than the graph of g(x).

E)The vertical distance between the vertex of f(x) and the vertex of g(x) is 4 units.

Answers

Answer:

A, D

Step-by-step explanation:

graphed each function and looked at graphs to determine which statements were true

Answer 6. Answer ASAP pls pls answer ASAP ASAP pls pls ASAP pls pls ASAP

Answers

2
5x10=50
5x2=10; 10x2=20
10x20=200

Answer:

2

Step-by-step explanation:

5x10=50

5x2=10; 10x2=20

10x20=200

Solve the equation 10^(4x−1)=2^5. Round your answer to the nearest hundredth


HELPPP!!

Answers

You can use the website “Wolfrum Alpha” for answers, it’s great and I use it for math all the time. Also could you please get me brainliest?

A factory produces bags of rubber bands. A bag of rubber bands has five different sizes: extra large (XL), large (L), medium (M), small (S), and extra small (XS). A quality control specialist collects a random sample of 450 rubber bands from the bagging machine and calculates a chi-square goodness-of-fit test to see if the frequencies for each size in the sample match the hypothesized distribution. The quality control specialist will test his sample against the following null hypothesis.H0:pXL=0.10,pL=0.20,pM=0.40,pS=0.20,pXS=0.10 How many medium rubber bands are expected in the random sample of 450 rubber bands?

Answers

Answer:

The expected frequency is 90

Step-by-step explanation:

If the given probabilities are taken as observed

pXL=0.10,      450*0.1= 45

pL=0.20,      450*0.2= 90

pM=0.40,     450*0.4= 180

pS=0.20,     450*0.2= 90

pXS=0.10     450*0.1= 45

We can assign the expected frequencies to be 450/5= 90 each

The chi square goodness fit test can be calculated as

Observed    Expected   (o-e)       (o-e)²          (o-e)² /e

45                   90         -45            2025              22.5

90                  90           0                0                    0

180                 90           90             8100               90

90                 90            0              0                         0

45                  90         -45             2025                   22.5    

∑                                                                                135        

χ²= 135

The χ² value at 0.05 is 9.49

The result is significant.

Answer:

180

Just took the test

The business college computing center wants to determine the proportion of business students who have laptop computers. If the proportion differs from 25%, then the lab will modify a proposed enlargement of its facilities. Suppose a hypothesis test is conducted and the test statistic is 2.4. Find the p-value for a two-tailed test of hypothesis.

Answers

Answer:

The p-value for a two-tailed test of hypothesis is 0.0164.

Step-by-step explanation:

The test statistic is 2.4. Find the p-value for a two-tailed test of hypothesis.

This means that we look at the z-table, and we have to find:

[tex]P(|Z| > 2.4)[/tex]

Which is the pvalue of Z = -2.4 multiplied by 2, or 2 multiplied by 1 subtracted by the pvalue of Z = 2.4.

Looking at the z-table, z = 2.4 has a pvalue of 0.9918

1 - 0.9918 = 0.0082

2*0.0082 = 0.0164

The p-value for a two-tailed test of hypothesis is 0.0164.

Which rational number equals 0 point 3 with bar over 3? Question 2 options: 1) 1 over 5 2) 1 over 3 3) 3 over 10 4) 3 over 5

Answers

9514 1404 393

Answer:

 2) 1/3

Step-by-step explanation:

The repeating decimal can be converted to a fraction by multiplying it by 10^n and subtracting the original value. n = number of repeating digits. This process cancels all of the repeating digits, so you can find the equivalent fraction.

  [tex]x=0.\overline{3}\\\\10x -x=3.\overline{3}-0.\overline{3}=3\\\\x=\dfrac{3}{9}\\\\0.\overline{3}=\dfrac{1}{3}[/tex]

_____

Your calculator can help you answer this:

  1/5 = 0.2

  1/3 = 0.333.... (repeating) . . . . the number you're looking for

  3/10 = 0.3

  3/5 = 0.6

Two lines, A and B, are represented by the following equations:

Line A: 2x + y = 6
Line B: x + y = 4

Which statement is true about the solution to the set of equations? (4 points)

a It is (2, 2).

b There are infinitely many solutions.

c It is (4, 0).

d There is no solution.

Answers

Answer:

The answer is B! if you want to do more of these problems may I recommend using Desmos?

Answer:

It is (2, 2).

Step-by-step explanation:

Help asap! First response= Brainliest!!

Answers

Answer:

3/3

Step-by-step explanation:

here ya go

Find the measure of <4.
{{
24
158°
KE
* 4 = [?]

Answers

<4=22°

Answer:

<4+158=180 co interior angle

<4=180-158=22°

Answer:

solution given:

<4+<158°=180°[co- interior angle]

<4=180°-<158°=22°

<4=22° is your answer

Arnold's entire workout consisted of 10 minutes of warm up exercise, 25 minutes of lifting weights, and 15 minutes on the treadmill. What was the ratio of the number of minutes he lifted weights to the total number of minutes of his entire workout?

Answers

Add all the times together:

10 + 25 + 15 = 50 minutes total.

For the ratio divide the time for weights by total time:

25/50 which reduces to 1/2

The ratio is 1/2

Answer:

15:50 = 3:10

3:10 is the answer

Which is the solution to the inequality?

1/4+x<5/6

A: x<7/12

B: x>7/12

C: x<1 1/12

D: x> 1 1/12​

Answers

Answer: x<7/12

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

to isolate 'x', subtract 1/4 from 5/6

you can use a common denominator of 12

1/4 = 3/12

5/6 = 10/12

x < 10/12 - 3/12

x < 7/12

I Need all the help please?

Answers

The answer is A because x-c is factor of p(x) mean
x-c=0
X =c
Then p(c)=0

PLEASE HURRY!!!! 100 POINTS

What is the unit rate of each snack?

Answers

Answer:

34.9

Step-by-step explanation:

Yes. : )

How to do subtract 1.7 from 3 show your work

Answers

3-1.7 = 1.3 this should be what your looking for

The length of a rectangle is 4 inches longer than its width. The area of the rectangle is 32 inches square. What is the width ? The width is ___ inches

Answers

Answer:

I hope this helps dear

Step-by-step explanation:

P = 2(L + W) = 32 in

L = W + 4

2[(W + 4) + W] = 32 in ⇒

W = 6 in

L = W + 4 = (6 + 4) in = 10 in

A = LW = (10)(6) in2 = 60 in2

Please Help
Due today

Answers

The solution using the method of substitution are:

1) Substitution in mathematics is the name given to the process of swapping an algebraic letter for its value.

2) PEMDAS Order of operations

3) 8

4) 91

What is substitution in mathematics?

Substitution in mathematics is the name given to the process of swapping an algebraic letter for its value. Consider the expression 5x + 2. This can take on a range of values depending on what number actually is. If we are told x = 4, we can work out the value of the expression by swapping the for the number 4.

The substitution operation must follow the algebraic order of operations.

3) (x + 5)² - y when x = -2 and y = 1

Thus:

(-2 + 5)² - 1

= 9 - 1

= 8

4) 3x + 4y² when x = -3 and y = 5

Thus:

3(-3) + 4(5)² = -9 + 100

= 91

Read more about substitution at: https://brainly.com/question/26094713

#SPJ1

PLEASE HELP ASAP!!!

What is the surface area of the prism below?

Answers

The prism below is 48

13. Ochieng had sh. 250 as pocket money at the beginning of the term. In the middle of the
term, he was left with 2/5 of this amount. How much did he spend?​

Answers

Answer:

sh.150.00

Step-by-step explanation:

2÷5×250

=100

250-100

=150

Can you help me with this please!?

Answers

9514 1404 393

Answer:

  (a)  2021

Step-by-step explanation:

The expression can be simplified.

  [tex]\displaystyle\frac{a^4+b^4+2a^2b^2+a^3b+ab^3}{a^2+b^2}+ab=\frac{(a^2+b^2)^2+ab(a^2+b^2)}{a^2+b^2}+ab\\\\=a^2+b^2+ab+ab=(a+b)^2\\\\=(\sqrt{2021})^2=\boxed{2021}[/tex]

Find the equation (in terms of x) of the line through the points (-2,-4) and (2,8) y=

Answers

Answer:

y = 3x + 2

Step-by-step explanation:

Hellpppppppppppppppppppppppppppppppppppppppp

Answers

Answer:

._.     -_-     -.-    .-.   --__--

Step-by-step explanation:

Find AC
A
-y + 23
B
c
бу +2
3
20
23
26

Answers

Answer:

yfvhbjnk.bdfxgvhjnmbgytfrgvnhjkm

Step-by-step explanation:

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