(Small sample confidence intervals for a population mean) suppose you are taking a sampling of 15 measurements. you find that x=75 and s =5. assuming normality, the 99% confidence interval for the population mean is:__________

Step-by-step explanation:

Here are some examples of ten integers (in this case prime numbers) chosen from 2 to 24;

2, 3, 5, 7, 9, 15, 17, 19, 21, 23

Lets take for example the integers 15 and 21, they have a common divisor 3 which is greater than 1. Which implies that the number 3 can divide through 15 and 21 without a remainder, that is, 21 ÷ 3 = 7, 15 ÷ 3 = 5. Also note that 3 is a divisor of 9.

Therefore, we could right say that within any set of ten integers chosen from 2 through 24, there are at least two integers with a common divisor greater than 1.

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▹ Answer

(10, -1)

▹ Step-by-Step Explanation

x - y = 11

2x + y = 19

Sum up the equations:

3x = 30

Divide 3 on both sides:

x = 10

Substitute:

10 - y = 11

y = -1

Solution:

(x, y) (10, -1)

Hope this helps!

CloutAnswers ❁

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Correct question is;

The U.S. Dairy Industry wants to estimate the mean yearly milk consumption. A sample of 21 people reveals the mean yearly consumption to be 74 gallons with a standard deviation of 16 gallons.

a. What is the value of the population mean? What is the best estimate of this value?

b. Explain why we need to use the t distribution. What assumption do you need to make?

c. For a 90 percent confidence interval, what is the value of t?

d. Develop the 90 percent confidence interval for the population mean.

e. Would it be reasonable to conclude that the population mean is 68 gallons?

Answer:

A) Best estimate = 74 gallons

B) because the population standard deviation is unknown. The assumption we will make is that the population follows the normal distribution.

C) t = 1.725

D) 90% confidence interval for the population mean is (67.9772, 80.0228) gallons

E) Yes

Step-by-step explanation:

We are given;

Sample mean; x' = 74

Sample population; n = 21

Yearly Standard deviation; s = 16

A) We are not given the population mean.

So the closest estimate to the population mean would be the sample mean which is 74.

B) We are not given the population standard deviation and as such we can't use normal distribution. So what is used when population standard deviation is not known is called t - distribution table. The assumption we will make is that the population follows the normal distribution.

C) At confidence interval of 90% and DF = n - 1 = 21 - 1 = 20

From t-tables, the t = 1.725

D) Formula for the confidence interval is;

x' ± t(s/√n) = 74 ± 1.725(16/√21) = 74 ± 6.0228 = 67.9772 or 80.0228

Thus 90% confidence interval for the population mean is (67.9772, 80.0228) gallons

E) 68 gallons lies within the range of the confidence interval, thus we can say that "Yes, it is reasonable"

Answer:

Step-by-step explanation:

If the rate of change of sales is inversely proportional to the time t, this is expressed mathematically as ΔS ∝ 1/Δt

ΔS = k/Δt where k is the constant of proportionality

If ΔS = S₂-S₁ and Δt = t₂-t₁

S₂-S₁ = k/ t₂-t₁

If the sales after 2 and 4 weeks are 162 units and 287 units respectively, then when S₁  = 162, t₁ = 2 and when   S₂ = 287, t₂ = 4.

On substituting this values into the given functions, we will have;

287 - 162 = k/4-2

125 = k/2

cross multiplying

k = 125* 2

k = 250

Substituting k = 250 into the function ΔS = k/Δt

ΔS = 250/Δt

S = 250/t

Hence the value of S as function of t when the sales after 2 and 4 weeks are 162 units and 287 units, respectively is expressed as S = 250/t

[tex] \Large{ \boxed{ \bf{ \color{purple}{Solution:}}}}[/tex]

Let the smaller angle be x

Then, Larger angle would be x + 4°

❍ They are complementary angles.

So,

➙ x + x + 4° = 90°

➙ 2x + 4° = 90°

➙ 2x = 86°

➙ x = 86°/2 = 43°

Then, x + 4° = 47°

So, Our required answer:

❍ They are supplementary angles.

So,

➙ x + x + 4° = 180°

➙ 2x + 4° = 180°

➙ 2x = 176°

➙ x = 176°/2 = 88°

Then, x + 4° = 92°

So, Our required answer:

✌️ Hence, solved !!

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Answer:

y = 11.19 ; 0.839

Step-by-step explanation:

Given the following :

relationship between hours of TV watched per day (x) and the number of sit-ups a person can do (y)

y = a + bx ; comparing with the linear regression model function

y = predicted variable

a = intercept

b = slope or gradient

x = independent variable

b = -0.89 a = 23.65 r2 = 0.7038

Therefore, if a person watches for 14 hours per day, that is x = 14, the number of sit-ups he can do will be :

y = 23.65 + (-0.89)(14)

y = 23.65 - 12.46

y = 11.19

About 11 sit-ups.

If the r^2 value = 0.7038

Then the Coefficient of regression = r

Will be the square root of r^2

r = sqrt(r^2)

r = sqrt(0.7038)

r =0.8389278 = 0.839

Answer:

to provide interest in the subject

As per my experience,I used to hate math and always scored less marks,the moment I was going to high school I realized the importance of math towards the future, see you'll find maths in nearly all subjects like the 3 sciences, economics, geography, business e.t.c

Why did you write this question at first?, just take some free time and think about it,the only best way to learn maths is to take maths positively as the best and most valuable subject,if you want to ace math you have to race it, challenge math like you'd challenge anyone to a game, practice math if it's your weakest point, practice is very much needed to skill maths and never be shy to ask your teachers whether you are studying online/offline. You'll need to get the shy behaviour out of you whether you like /don't like your teacher or your an average student.

Concentrate while learning math, whether there's noise in you background or not, Nothing can stop you in excelling math if you have full concentration, positiveness and the "will" to do so.

if you're next to your exams then just one thing, Start now!!

hope this helps!

Answer:

64 : 729

Step-by-step explanation:

Ratio of surface area

= (ratio of linear dimensions) ^2

= 1.6^2 : 5.4^2

= 256 : 2916

= 64 : 729

Answer:

(4) → (1) → (3) → (2)

Step-by-step explanation:

Order of operations in any question are decided by the rule,

P → Parentheses

E → Exponents

D → Division

M → Multiplication

A → Addition

S → Subtract

Following the same rule order of operations will be,

- Take care of anything inside the parentheses.

- Evaluate and raise the exponents

- Multiply or divide. Make sure to do whichever one comes first from left to right.

- Add or Subtract from left to right.

Options are arranged in the order of,

(4) → (1) → (3) → (2)

Answer:

C

Step-by-step explanation:

The area (A) of a circle is calculated as

A = πr² ( r is the radius )

Here r = 18 cm , thus

A = π × 18² = 324π ≈ 1017.9 cm² → C

Answer:

C.) 1017.9 cm²

Step-by-step explanation:

For a given circle

radius (r) = 18 cm

Now,

Area of Circle

= πr²

= 3.14 × (18)² cm

= 3.14 × 324 cm

= 1017.9 cm²

Answer:

let x be y

NOW,

X+6Y=6

Y+6Y=6

7Y=6

Y=0.87

Answer:

(a) The probability that X is at most 30 is 0.9726.

(b) The probability that X is less than 30 is 0.9554.

(c) The probability that X is between 15 and 25 (inclusive) is 0.7406.

Step-by-step explanation:

We are given that 11% of all steel shafts produced by a certain process are nonconforming but can be reworked. A random sample of 200 shafts is taken.

Let X = the number among these that are nonconforming and can be reworked

The above situation can be represented through binomial distribution such that X ~ Binom(n = 200, p = 0.11).

Here the probability of success is 11% that this much % of all steel shafts produced by a certain process are nonconforming but can be reworked.

Now, here to calculate the probability we will use normal approximation because the sample size if very large(i.e. greater than 30).

So, the new mean of X, [tex]\mu[/tex] = [tex]n \times p[/tex] = [tex]200 \times 0.11[/tex] = 22

and the new standard deviation of X, [tex]\sigma[/tex] = [tex]\sqrt{n \times p \times (1-p)}[/tex]

                                                                  = [tex]\sqrt{200 \times 0.11 \times (1-0.11)}[/tex]

                                                                  = 4.42

So, X ~ Normal([tex]\mu =22, \sigma^{2} = 4.42^{2}[/tex])

(a) The probability that X is at most 30 is given by = P(X < 30.5)  {using continuity correction}

        P(X < 30.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{30.5-22}{4.42}[/tex] ) = P(Z < 1.92) = 0.9726

The above probability is calculated by looking at the value of x = 1.92 in the z table which has an area of 0.9726.

(b) The probability that X is less than 30 is given by = P(X [tex]\leq[/tex] 29.5)    {using continuity correction}

        P(X [tex]\leq[/tex] 29.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] [tex]\leq[/tex] [tex]\frac{29.5-22}{4.42}[/tex] ) = P(Z [tex]\leq[/tex] 1.70) = 0.9554

The above probability is calculated by looking at the value of x = 1.70 in the z table which has an area of 0.9554.

(c) The probability that X is between 15 and 25 (inclusive) is given by = P(15 [tex]\leq[/tex] X [tex]\leq[/tex] 25) = P(X < 25.5) - P(X [tex]\leq[/tex] 14.5)   {using continuity correction}

       P(X < 25.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{25.5-22}{4.42}[/tex] ) = P(Z < 0.79) = 0.7852

       P(X [tex]\leq[/tex] 14.5) = P( [tex]\frac{X-\mu}{\sigma}[/tex] [tex]\leq[/tex] [tex]\frac{14.5-22}{4.42}[/tex] ) = P(Z [tex]\leq[/tex] -1.70) = 1 - P(Z < 1.70)

                                                          = 1 - 0.9554 = 0.0446

The above probability is calculated by looking at the value of x = 0.79 and x = 1.70 in the z table which has an area of 0.7852 and 0.9554.

Therefore, P(15 [tex]\leq[/tex] X [tex]\leq[/tex] 25) = 0.7852 - 0.0446 = 0.7406.

Answer:

129 [tex]cm^2/s[/tex]

Step-by-step explanation:

Increasing rate of length, [tex]\frac{dl}{dt}[/tex]= 9 cm/s

Increasing rate of width, [tex]\frac{dw}{dt}[/tex] = 7 cm/s

Length, l = 12 cm

Width, w = 5 cm

To find:

Rate of increase of area of rectangle at above given points.

Solution:

Formula for area of a rectangle is given as:

[tex]Area = Length \times Width[/tex]

OR

[tex]A = l \times w[/tex]

Differentiating w.r.to t:

[tex]\dfrac{d}{dt}A = \dfrac{d}{dt}(l \times w)\\\Rightarrow \dfrac{d}{dt}A = w \times \dfrac{d}{dt}l +l \times \dfrac{d}{dt}w[/tex]

Putting the values:

[tex]\Rightarrow \dfrac{dA}{dt} = 5 \times 9 + 12 \times 7\\\Rightarrow \dfrac{dA}{dt} = 45 + 84\\\Rightarrow \bold{\dfrac{dA}{dt} = 129\ cm^2/sec}[/tex]

Answer:

x=24

Step-by-step explanation:

3/4(x-8)=12

3/4x-24/4=12

3/4x=18

18 dived by 3/4

x=24

your welcome :)

Answer:

The probability of getting an offspring pea that is green is is 0.733

YES, the probability is reasonably close to the expected value of 3/4 (0.750)

Step-by-step explanation:

The formula for calculating the probability of an event is;

P = Favorable Outcome / Sample space

Let A be an event of getting an offspring green peas, B be an event of getting an offspring yellow peas and N be the total number of peas.

number of green peas in an offspring are 350

number of yellow peas in an offspring are 127

total number of peas are 477    

So in the genetic experiment, the number of times event A occurs is 350 and the number times event B occurs is 127

Now the probability of getting an offspring pea that is green is

P = number of green peas / total number of peas

p = n(A)/N

p = 350/477

p = 0.733

So YES, the probability is reasonably close to 3/4 ( 0.750 )

The probability of getting an offspring pea that is green is is 0.733.

YES, the probability is reasonably close to the expected value of 3/4 (0.750)

Answer:

Infinite number of solutions.

Step-by-step explanation:

There are an infinite number of solutions.  If you graph both lines, you find they are the same line.  If you multiply the send equation by -4, you’ll end up with the first equation.  I’m not sure what your teacher means by specifying their form.

Answer:

the person above is correct if i did this correct

Step-by-step explanation:

Answer:

B: -x^2 + 4

Step-by-step explanation:

If the equation was [tex]f(x)=x^2[/tex], then the vertex would be at 0, and the "U" would be facing straight up. Here, the "U" is upside down, so that means the "x^2" would have to be a negative number ([tex]-x^2[/tex]) to get the upside-down "U". Then, we could see that the vertex is at positive 4, so that means that the parabola moved up 4 units, so the equation should end in +4.

Our answer is:

B: -x^2 + 4

Answer:

135 degrees

Step-by-step explanation:

3x+15 = 5x - 5 because of the alternate interior angles theorem.

20 = 2x

x = 10

3(10) + 15 = 30+15 = 45

Remember that a line has a measure of 180 degrees. So we can just subtract the angle we found from 180 degrees to get BFG.

180-45 = 135.

1: 8 faces and 9 with the base 9 vertices and 16 edges

2: 3 faces and 5 with the bases 6 vertices and 9 edges

3: 3 faces and 4 with the base 4 vertices and 6 edges

Hope this can help you.

1: 8 faces and 9 with the base 9 vertices and 16 edges

2: 3 faces and 5 with the bases 6 vertices and 9 edges

3: 3 faces and 4 with the base 4 vertices and 6 edges

Hi there! :)

Answer:

[tex]\huge\boxed{a < 5}[/tex]

Given:

7a + 13 < 48

Isolate the variable "a" by subtracting 13 from both sides:

7a - 13 < 48 - 13

7a < 35

Divide both sides by 7:

7a/7 < 35/7

a < 5.

Answer:

a < 5

Step-by-step explanation:

7a + 13 < 48

Subtract 13 from each side

7a + 13-13 < 48-13

7a < 35

Divide each side by 7

7a/7  < 35/7

a < 5

Answer:

  16%

Step-by-step explanation:

The difference between the time of interest (339 days) and the mean (336 days) is 3 days, which is exactly 1 standard deviation.

The 68-95-99.7 rule tells you that 68% of pregnancies will be within 1 standard deviation. The remaining 32% will be evenly split between pregnancies that are longer than 339 days and ones that are shorter than 333 days. So, half of 32%, or 16%, will be longer than 339 days.

Answer:

3.25

Step-by-step explanation:

Answer:

$2,589.52

Step-by-step explanation:

[tex] A = P(1 + \dfrac{r}{n})^{nt} [/tex]

We start with the compound interest formula above, where

A = future value

P = principal amount invested

r = annual rate of interest written as a decimal

n = number of times interest is compound per year

t = number of years

For this problem, we have

P = 2000

r = 0.026

n = 2

t = 10,

and we find A.

[tex] A = $2000(1 + \dfrac{0.026}{2})^{2 \times 10} [/tex]

[tex] A = $2589.52 [/tex]

Compound interest formula:

Total = principal x ( 1 + interest rate/compound) ^ (compounds x years)

Total = 2000 x 1+ 0.026/2^20

Total = $2,589.52

Answer:

The​ z-score for 1880 is 1.34.

The​ z-score for 1190 is -0.88.

The​ z-score for 2130 is 2.15.

The​ z-score for 1350 is -0.37.

And the z-score of 2130 is considered to be unusual.

Step-by-step explanation:

The complete question is: A standardized​ exam's scores are normally distributed. In recent​ years, the mean test score was 1464 and the standard deviation was 310. The test scores of four students selected at random are ​1880, 1190​, 2130​, and 1350. Find the​ z-scores that correspond to each value and determine whether any of the values are unusual. The​ z-score for 1880 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 1190 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 2130 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 1350 is nothing. ​(Round to two decimal places as​ needed.) Which​ values, if​ any, are​ unusual? Select the correct choice below​ and, if​ necessary, fill in the answer box within your choice. A. The unusual​ value(s) is/are nothing. ​(Use a comma to separate answers as​ needed.) B. None of the values are unusual.

We are given that the mean test score was 1464 and the standard deviation was 310.

Let X = standardized​ exam's scores

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 test score = 1464

           [tex]\sigma[/tex] = standard deviation = 310

S, X ~ Normal([tex]\mu=1464, \sigma^{2} = 310^{2}[/tex])

Now, the test scores of four students selected at random are ​1880, 1190​, 2130​, and 1350.

So, the z-score of 1880 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                      =  [tex]\frac{1880-1464}{310}[/tex]  = 1.34

The z-score of 1190 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{1190-1464}{310}[/tex]  = -0.88

The z-score of 2130 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{2130-1464}{310}[/tex]  = 2.15

The z-score of 1350 =  [tex]\frac{X-\mu}{\sigma}[/tex]

                                =  [tex]\frac{1350-1464}{310}[/tex]  = -0.37

Now, the values whose z-score is less than -1.96 or higher than 1.96 are considered to be unusual.

According to our z-scores, only the z-score of 2130 is considered to be unusual as all other z-scores lie within the range of -1.96 and 1.96.

Answer:

  -3

Step-by-step explanation:

If these numbers are part of an arithmetic progression, their differences are the same:

  (x -7) -(2x +1) = (2x +1) -(x +3)

  -x -8 = x -2

  -6 = 2x

  -3 = x

___

The numbers in the sequence are 0, -5, -10.

Answer:

x = -3.

Step-by-step explanation:

As it is an Arithmetic Progression the differences between successive terms are common, so:

2x + 1 - (x + 3) = x - 7 - (2x + 1)

2x - x + 1 - 3 = x - 2x - 7 - 1

x - 2 = -x - 8

2x = -8 + 2 = -6

x = -3.

THIS IS THE COMPLETE QUESTION BELOW

The demand equation for a product is p=90000/400+3x where p is the price (in dollars) and x is the number of units (in thousands). Find the average price p on the interval 40 ≤ x ≤ 50.

Answer

$168.27

Step by step Explanation

Given p=90000/400+3x

With the limits of 40 to 50

Then we need the integral in the form below to find the average price

1/(g-d)∫ⁿₐf(x)dx

Where n= 40 and a= 50, then if we substitute p and the limits then we integrate

1/(50-40)∫⁵⁰₄₀(90000/400+3x)

1/10∫⁵⁰₄₀(90000/400+3x)

If we perform some factorization we have

90000/(10)(3)∫3dx/(400+3x)

3000[ln400+3x]₄₀⁵⁰

Then let substitute the upper and lower limits we have

3000[ln400+3(50)]-ln[400+3(40]

30000[ln550-ln520]

3000[6.3099×6.254]

3000[0.056]

=168.27

the average price p on the interval 40 ≤ x ≤ 50 is

=$168.27