Help Me Please.............................(7)

Answer:

The t-distribution is used, as we have the standard deviation of the sample.

The 95% confidence interval for the population mean time wasted is between 7.12 hours and 8.88 hours.

Step-by-step explanation:

We have the standard deviation for the sample, which meas that the t-distribution should be used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 81 - 1 = 80

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 80 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 1.99

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.99\frac{4}{\sqrt{81}} = 0.88[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 8 - 0.88 = 7.12 hours.

The upper end of the interval is the sample mean added to M. So it is 8 + 0.88 = 8.88 hours.

The 95% confidence interval for the population mean time wasted is between 7.12 hours and 8.88 hours.

Answer:

B and D

Step-by-step explanation:

A would be:

57 + 2j

C would be:

13-t

Answer:

[tex]H'I = 48[/tex]

Step-by-step explanation:

Given

See attachment for complete question.

From the attachment, we have:

[tex]GH=16.5[/tex]

[tex]HI =24[/tex]

[tex]IJ = 17[/tex]

[tex]JG =32.2[/tex]

[tex]k = 2[/tex] --- Scale factor

Required

Find H'I

The corresponding side of H'I is HI.

So:

H'I is calculated as:

[tex]H'I = k * HI[/tex]

This gives:

[tex]H'I = 2 * 24[/tex]

[tex]H'I = 48[/tex]

Answer I to j is 42

Step-by-step explanation:

Answer:

isn't it just 50°

Step-by-step explanation:

180=a straight line.

you are given 75° and 55°

75+55=130

180-130

Answer:

105

Step-by-step explanation:

Chupapi

Some loser deleted my answers

That's why it says 1 answer and 1.5k people helped

Answer:

Its 5,...................

Answer:

5

Step-by-step explanation:

simplify the exponent

35/8-1

simplify

35/7

simplify

5

Answer:

117π or 367.56634047

Step-by-step explanation:

Volume = π × r² × h          (r=radius and h=height)

Volume = π × 4² × 13

Volume = π × 9 × 13

Volume = π × 117

Volume = 117π

Step-by-step explanation:

[tex]sinθ = \frac{3}{5} \: \: cosθ = \frac{4}{5} \\ now \\ tanθ = \frac{sinθ}{cos θ } \\ = \frac{3}{5 } \div \frac{4}{5} \\ = \frac{3}{5} \times \frac{5}{4} \\ = \frac{3}{4} [/tex]

Hope it will help :)❤

Answer:

52

Step-by-step explanation:

when a letter is next to a number like that and they tell u what the letter is u times it so 6x7+10=52 hope this helped :P

Answer:

Step-by-step explanation:

The parallelogram is two congruent triangles. Area of blue triangle is ½·2·2 = 2 units²

Area of parallelogram = 4 units²

:::::

area of blue parallelogram = 4×9 = 36 units²

:::::

area of green parallelogram = 3×5 = 15 units²

Answer:

Matching Tiles with Terms:

Term                                                Example                                    

NOT a Representative Sample      Drivers who reside in Middlefield

Population                                       Residents of Middlefield            

Representative Sample                  Residents randomly chosen from the

                                                        town register

Step-by-step explanation:

Population includes all the residents of Middlefield.

Representative Sample is a population subset that accurately reflects the characteristics of the population.  For example, the subset of residents who are randomly chosen from the town register is an unbiased and representative sample.

NOT a Representative Sample: For example, drivers who reside in Middlefield do not represent the characteristics of the population of Middlefield.

Answer:

a) the probability of a length of stay greater than 10 hours is 0.03144

b) the length of stay is exceeded by 25% of the visits is 6.5 hrs

c)

P( X < 0 ) = 0.0559

The probability of length of stay less than 0 hours is 0.0559, length of stay cannot be less than 0. When the normal model is used, we assume that the LOF is approximately normally distributed.

The LOF is better modeled by the normal distribution near the mean and worse in the tails.

The probabilities in the left tail for the vales of X < 0  can be neglected.

Step-by-step explanation:

Given that;

mean μ = 4.6

standard deviation σ = 2.9

let x represent length of stay;

a. What is the probability of a length of stay greater than 10 hours?

p( x > 10 ) = p( x-μ/σ > 10-4.6 / 2.9 )

= p( Z > 1.86)

= P( Z < - 1.86 )

FROM THE Z SCORE TABLE;( Z < - 1.86 ) = 0.03144

p( x > 10 )  = 0.03144

Therefore, the probability of a length of stay greater than 10 hours is 0.03144

b) What length of stay is exceeded by 25% of the visits?

p( X > x ) = 0.25

so

p( X < x ) = 0.75

p( x-μ/σ < x-4.6 / 2.9 ) = 75

p( Z < x-4.6 / 2.9 ) = 0.75 ----- 1

also, from the standard normal table; P( Z < 0.67 ) = 0.75 ------ 11

from equation 1 and 11

x-4.6 / 2.9 = 0.67

x-4.6 = 2.9 × 0.67

x - 4.6 = 1.943

x = 4.6 + 1.943

x = 6.543 ≈ 6.5

Therefore, the length of stay is exceeded by 25% of the visits is 6.5 hrs

c)  From the normally distributed model, what is the probability of a length of stay less than 0 hours?

P( X < 0 ) = p( x-μ/σ < 0-4.6 / 2.9 )

= P( Z - 1.59)

from table;( Z - 1.59) = 0.0559

P( X < 0 ) = 0.0559

The probability of length of stay less than 0 hours is 0.0559, length of stay cannot be less than 0. When the normal model is used, we assume that the LOF is approximately normally distributed.

The LOF is better modeled by the normal distribution near the mean and worse in the tails.

The probabilities in the left tail for the vales of X < 0  can be neglected.  

Answer:

26mm

Step-by-step explanation:

by the Pythagorean theorem,

[tex]x^2=10^2+24^2\\x^2=676\\x=26[/tex]

Answer:

[tex]1\frac{1}{2}[/tex] miles = 7920 feet

2[tex]\frac{1}{2}[/tex] miles = 13200 feet

3[tex]\frac{1}{2}[/tex] miles = 18480 feet

4[tex]\frac{1}{2}[/tex] miles = 23760 feet

5[tex]\frac{1}{2}[/tex] miles = 29040 feet

6[tex]\frac{1}{2}[/tex] miles = 34320 feet

Explanation:

1 mile = 5280 feet

[tex]\frac{1}{2}[/tex] miles = 2640 feet

to convert miles into feet, multiply the whole numbers by 5280 and add 2640 to find your overall feet

2[tex]\frac{1}{2}[/tex] : 2 x 5280 + 2640 = 13200 ft

3[tex]\frac{1}{2}[/tex] : 3 x 5280 + 2640 = 18480 ft

4[tex]\frac{1}{2}[/tex] : 4 x 5280 + 2640 = 23760 ft

5[tex]\frac{1}{2}[/tex] : 5 x 5280 + 2640 = 29040 ft

6[tex]\frac{1}{2}[/tex] : 6 x 5280 + 2640 = 34320 ft

Answer:

NO POSSIBLE TRIANGLES

Step-by-step explanation:

Answer:

no possible triangles

Step-by-step explanation:

Answer:

6/2

Step-by-step explanation:

The slope of the given line is 3/1, Option D is correct.

The given line is passing through the points (1, 3) and (-1, -3)

The slope of line passing through two points (x₁, y₁) and (x₂, y₂) is

m=y₂-y₁/x₂-x₁

Plug in the values of points  (1, 3) and (-1, -3) in the formula.

m= -3-3/-1-1

=-6/-2

Divide numerator and denominator by 2

We get 3

Slope of the line is 3.

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Answer:

I think the answer is $14 hope this helps!

Step-by-step explanation:

Answer:

a) 0.0000001024 probability that he will answer all questions correctly.

b) 0.1074 = 10.74% probability that he will answer all questions incorrectly

c) 0.8926 = 89.26% probability that he will answer at least one of the questions correctly.

d) 0.0328 = 3.28% probability that Richard will answer at least half the questions correctly

Step-by-step explanation:

For each question, there are only two possible outcomes. Either he answers it correctly, or he does not. The probability of answering a question correctly is independent of any other question. This means that we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

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

And p is the probability of X happening.

Each question has five answers, of which only one is correct

This means that the probability of correctly answering a question guessing is [tex]p = \frac{1}{5} = 0.2[/tex]

10 questions.

This means that [tex]n = 10[/tex]

A) What is the probability that he will answer all questions correctly?

This is [tex]P(X = 10)[/tex]

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} = 0.0000001024[/tex]

0.0000001024 probability that he will answer all questions correctly.

B) What is the probability that he will answer all questions incorrectly?

None correctly, so [tex]P(X = 0)[/tex]

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{10,0}.(0.2)^{0}.(0.8)^{10} = 0.1074[/tex]

0.1074 = 10.74% probability that he will answer all questions incorrectly

C) What is the probability that he will answer at least one of the questions correctly?

This is

[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]

Since [tex]P(X = 0) = 0.1074[/tex], from item b.

[tex]P(X \geq 1) = 1 - 0.1074 = 0.8926[/tex]

0.8926 = 89.26% probability that he will answer at least one of the questions correctly.

D) What is the probability that Richard will answer at least half the questions correctly?

This is

[tex]P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 5) = C_{10,5}.(0.2)^{5}.(0.8)^{5} = 0.0264[/tex]

[tex]P(X = 6) = C_{10,6}.(0.2)^{6}.(0.8)^{4} = 0.0055[/tex]

[tex]P(X = 7) = C_{10,7}.(0.2)^{7}.(0.8)^{3} = 0.0008[/tex]

[tex]P(X = 8) = C_{10,8}.(0.2)^{8}.(0.8)^{2} = 0.0001[/tex]

[tex]P(X = 9) = C_{10,9}.(0.2)^{9}.(0.8)^{1} \approx 0[/tex]

[tex]P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} \approx 0[/tex]

So

[tex]P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.0264 + 0.0055 + 0.0008 + 0.0001 + 0 + 0 = 0.0328[/tex]

0.0328 = 3.28% probability that Richard will answer at least half the questions correctly

Answer:

12) Between 40 and 64 = 0.815

13) Between 32 and 40 = 0.0235

14) Between 56 and 64 = 0.34

15) At most 56 = 0.515

16) At least 72 = 0.025

17) At most 64 = 0.855

Explanation:

To answer this, we will convert each of the values into their standardized form to make this easier.

The standardized score for any value is the value minus the mean then divided by the standard deviation.

z = (x - μ)/σ

x = Each value

μ = Mean = 56

σ = Standard deviation = 8

12) Between 40 and 64

For 40,

z = (x - μ)/σ = (40 - 56)/8 = (-16/8) = -2

For 64

z = (x - μ)/σ = (64 - 56)/8 = (8/8) = 1

So,

Between 40 and 64 = Between -2 and 1

From the curve, noting that the central point is the mean, with standard score of 0, the lines before it move in step of 1 standard deviation towards the negative side, that is, -1, -2, etc. And the lines before the central point move towards the positive side, that is, 1, 2, 3, etc.

So,

Between -2 and 1 = 0.135 + 0.34 + 0.34 = 0.815

13) Between 32 and 40

For 32,

z = (x - μ)/σ = (32 - 56)/8 = (-24/8) = -3

For 40,

z = (x - μ)/σ = (40 - 56)/8 = (-16/8) = -2

So,

Between 32 and 40 = Between -3 and -2 = 0.0235

14) Between 56 and 64

For 56,

z = (x - μ)/σ = (56 - 56)/8 = (0/8) = 0

For 64,

z = (x - μ)/σ = (64 - 56)/8 = (8/8) = 1

Between 56 and 64 = Between 0 and 1 = 0.34

15) At most 56

For 56,

z = (x - μ)/σ = (56 - 56)/8 = (0/8) = 0

At most 56 = At most 0 = 0.0015 + 0.0235 + 0.15 + 0.34 = 0.515

All the regions before z = 0)

16) At least 72

For 72,

z = (x - μ)/σ = (72 - 56)/8 = (16/8) = 2

At least 72 = At least 2 = 0.0235 + 0.0015 = 0.025

(All the regions from z = 2 to the end)

17) At most 64

For 64,

z = (x - μ)/σ = (64 - 56)/8 = (8/8) = 1

At most 64 = At most 1 = 0.0015 + 0.0235 + 0.15 + 0.34 + 0.34 = 0.855

(All the regions before z = 1)

Hope this Helps!!!

Answer:

1. mean = 980 median = $895.5

2. 308, 593, 895.5, 1425, 1720

3. 491.7978

4. 895.5

5. 50.28%

Step-by-step explanation:

1. mean $1,589+$593+$1,223+$869+$423+$1,720+$708+$1,425+$922+$308/10

= 9780/10

= $978

median

We first arrange the values in ascending order

308,423,593,708,869,922,1223,1425,1589,1720

number of observation is even so we pick the 2 values in the middle and divide by 2

= 869+922/2

= $1791/2

$895.5

2. five number summary of change

the botom half of th dta set = 308,423,593,708,869

minimum value = 308

n = 5

median = 593 = q1

from 1, q2 = median = $895.5

the upper half of data

922,1223,1425,1589,1720

n = 5

median = $1425

maximum value = $1720

the five number summary of change in cost is therefore

308, 593, 895.5, 1425, 1720

3. standard deviation

[tex]s =[\sqrt{x-barx} ]^{2} \frac{1}{n-1}[/tex]

bar x is the mean = 978

($1,589-978)²+ ($593-978)²+ ($1,223-978)²+ ($869-978)+ ($423-978)²+ $1,720-978)²+($708-978)²+ ($1,425-978)²+ ($922-978)²+ ($308-978)²

= 2176786

=[tex]\sqrt\frac{1}{10-1} {2176786} \\\sqrt{ \frac{2176786}{9}[/tex]

= [tex]\sqrt{241865.1}[/tex]

= 491.7978

4.  middle 50% is spread over the median, which is 895.5

5.  coefficient of variation

= s/bar x * 100

= 491.7978/978 * 100

= 49179.78/978

= 50.28%

6. z score = x - mean/s

x = 1589

= 1589-978/491.7978

= 1.2424

for x = 593

593-978/491.7978

= -0.7828

= 0.7828

for x = 1223

1223-978/491.7978

= 0.4982

for x = 869

869-978/491.7978

= -0.2216

= 0.2216

for x = 423

423-978/491.7978

= -1.1285

= 1.1285

x = 1720

1720-978/491.7978

z = 1.5088

for x = 708

708-978/491.7978

= -0.5490

= 0.5490

for x = 1425

1425-978/491.7978

= 0.9089

for x = 922

922-978/491.7978

= -0.1139

= 0.1139

for x = 308

308-978/491.7978

= -1.3624

= 1.3624

Answer:

let L=lucy and A=ayu

l+a=1080

l=7a 7a+a=1080

8a=1080 8a/8=1080/8

ayu=135

l=7a l=7×135

l=945 so:-135+945=1080

Lucy sold 945 iPads and Ayu sold 135 iPads

"It is a mathematical statement which consists of equal symbol between two algebraic expressions."

For given question,

Let Lucy and Ayu sold 'x' and 'y' iPads respectively.

Lucy and Ayu sold a total of 1,080 iPads.

So, we get an equation,

⇒ x + y = 1080           ...............(i)

Lucy sold 7 times as many as Ayu.

So we get the second equation as,

⇒ x = 7y                     ................(ii)

Substitute above value of x in equation (i)

⇒ x + y = 1080

⇒ 7y + y = 1080

⇒ 8y = 1080

⇒ y = 135

This means, Ayu sold 135 iPads

Substitute above value of y in equation (ii)

⇒ x = 7(135)    

⇒ x = 7 × 135

⇒ x = 945

This means, Lucy sold 945 iPads.

Therefore, Lucy sold 945 iPads and Ayu sold 135 iPads

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Answer:

8/3

Step-by-step explanation:

x : 4 = 4 :  6

x = 16/ 6

x = 8/3

Answer:

hope this helps

The solution is 3,27,680

The geometric progression is given by aₙ = a ( r )ⁿ⁻¹ , where r = 4 is the common ratio and after 8 hours a₈ = 3,27,680

A geometric progression is a sequence in which each term is derived by multiplying or dividing the preceding term by a fixed number called the common ratio.

The nth term of a GP is aₙ = arⁿ⁻¹

The general form of a GP is a, ar, ar2, ar3 and so on

Sum of first n terms of a GP is Sₙ = a(rⁿ-1) / ( r - 1 )

Given data ,

Let the first term of the geometric sequence be a₁ = 20

Let the second term a₂ = 80

So , the common ratio r = second term / first term

On simplifying the equation , we get

Common ratio r = 80/20

Common ratio r = 4

Now , the explicit formula for the GP is

aₙ = a ( r )ⁿ⁻¹ , where n is the number of hours

aₙ = 20 ( 4 )ⁿ⁻¹

So , after 8 hours ,

Substitute the value of n = 8 in the equation , we get

a₈ = 20 ( 4 )ⁿ⁻¹

a₈ = 20 ( 4 )⁷

a₈ = 3,27,680

Therefore , the value of a₈ = 3,27,680

Hence , the equation is aₙ = 20 ( 4 )ⁿ⁻¹

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Answer:

Assumption A is violated

Step-by-step explanation:

x = number of blemishes = 8

n = sample size = 150

proportion = x/n = 8/150 = 0.0533

1. large counts: np> 10

= 150 * 0.0533 >10

= 7.995 > 10

this assumpton is obviously violated. 7.995 is not greater than 10

2. Large Counts: n(1 - p) > 10

150(1-0.0533)>10

150-7.995 > 10

142.005> 10

there is no violation. The assumption is satisfied

3. This assumption is satisfied. this is because the tomatoes were selected using simple random sampling.

4. 10% of the population = 0.1 * 2000 = 200

the sample size = 150

150 < 200

this assumption is satisfied

Answer:

0.98 = 98% probability that the average midterm score of these students is at most 75 points.

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 estabilishes 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.

The average midterm score of students in a certain course is 70 points.

This means that [tex]\mu = 70[/tex]

29 students are randomly selected and the standard deviation of their scores is found to be 13.15 points.

This means that [tex]\sigma = 13.15, n = 29, s = \frac{13.15}{\sqrt{29}} = 2.44[/tex]

Find the probability that the average midterm score of these students is at most 75 points.

This is the pvalue of Z when X = 75. So

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

By the Central Limit Theorem

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

[tex]Z = \frac{75 - 70}{2.44}[/tex]

[tex]Z = 2.05[/tex]

[tex]Z = 2.05[/tex] has a pvalue of 0.98.

0.98 = 98% probability that the average midterm score of these students is at most 75 points.

Answer:

Brainliest????

Step-by-step explanation:

X=23°

Answer:

C≈9.42m

Using any of this formulas

C=2πr

C=2πrd=2r

Solution:

C=πd=π·3≈9.42478m

Answer:

0.1

Step-by-step explanation: