A student measured the lead content of a paint sample 4 times. The standard deviation of the measurements was found to be 0.76% of the average. Calculate the confidence interval at the 90% confidence level.

Answers

Answer 1

Answer:

[tex]CI =0.894%[/tex]

Step-by-step explanation:

From the question we are told that:

Sample size [tex]n=4[/tex]

Standard deviation [tex]\sigma=0.76\% of \=x[/tex]

Confidence level [tex]\mu =90\%=0.90[/tex]

Degree of Freedom [tex]Df=n-1=3[/tex]

Therefore

Test T from table is given

 [tex]t=2.353[/tex]

Generally the equation for Confidence interval CI is mathematically given by

 [tex]CI =t*\frac{\sigma}{\sqrt{n}}[/tex]

 [tex]CI =2.353*\frac{0.76}{\sqrt{4}}[/tex]

 [tex]CI =0.894%[/tex]


Related Questions

Use technology to help you test the claim about the population mean, mu, at the given level of significance, alpha, using the given sample statistics. Assume the population is normally distributed.
Claim: μ>1220;α=0.08; σ=211.67.
Sample statistics: x=1235.91,n=300
Identify the null and alternative hypotheses and calculate the standardized test statistic.

Answers

Answer:

H0 : μ = 1220

H1 : μ > 1220

Test statistic = 1.30

Step-by-step explanation:

Sample mean, x = 1235.91

Standard deviation, σ = 211.67

Sample size, n = 300

The hypothesis :

Null ; H0 : μ = 1220

Alternative ; H1 : μ > 1220

Tbe test statistic :

(x - μ) ÷ (σ/√(n))

(1235.91 - 1220) ÷ (211.67/√(300))

15.91 / 12.220773

= 1.3018

= 1.30

Una librería consta de 5400 libros repartidos en 3 estanterías
En la estanteria A ahi el triple de libros que en la B y en la B la mitad que en la C calcular cuantos libros ahi en cada estanteria
Construir la ecuacion que plantea el problema

Answers

Answer:

B = 900 Libros

A = 2700 Libros

C = 1800 Libros

Step-by-step explanation:

A = 3B

2B = C

A + B + C = 5400

3B + B + 2B = 5400

6B = 5400

B = 5400 / 6

B = 900 Libros

A = 3B

A = 3(900)

A = 2700 Libros

C = 2B

C = 2(900)

C = 1800 Libros


The length of a rectangle should be 8 meters longer than 7 times the width. If the length must be
between 43 and 106 meters long, what are the restrictions for the width, x?

Answers

Answer:

The restrictions for x would be 14 > x > 5.

Step-by-step explanation:

Let the length of the rectangle be y and the width be x.

That being said, the equation would be as follows:

[tex]y = 7x + 8[/tex]

[tex]y - 8 = 7x[/tex]

[tex]x = \frac{y-8}{7}[/tex]

Therefore, substituting the two values of y into the equations, we would get:

[tex]x = \frac{43-8}{7}[/tex]

[tex]x = \frac{35}{7}[/tex]

[tex]x = 5[/tex]

And:

[tex]x = \frac{106-8}{7}[/tex]

[tex]x = \frac{98}{7}[/tex]

[tex]x = 14[/tex]

Therefore, x would be between 5 and 14, and the restrictions for x would be 14 > x > 5.

Hope this helped!

Which is shown by the map

Answers

Answer:

A

Step-by-step explanation:

Answer: A

Step-by-step explanation: Different colours show different parts of africa and the general language spoken by individuals. From the map show, there are a lot of languages in Africa.

What is 4+1 lets see how smart u sre

Answers

Answer:

its legit 5

Step-by-step explanation:

Answer:

Very tricky question..

4 + 1 is 5 because you have written 4+1 not 4 1

so 5 is correct answer

Step-by-step explanation:

hope it helps

Please help me esperas this!!

Answers

9514 1404 393

Answer:

  tan(φ) = (x² -1)/(2x)

Step-by-step explanation:

In a right triangle, the tangent of one of the acute angles is the ratio of the opposite side to the adjacent side. Here, the length of the adjacent side is not given, but can be found from the Pythagorean theorem.

  adjacent side = √((x² +1)² -(x² -1)²) = √((x⁴ +2x² +1) -(x⁴ -2x²+1))

  adjacent side = √(4x²) = 2x

Then the tangent ratio is ...

  tan(φ) = (opposite side)/(adjacent side)

  tan(φ) = (x² -1)/(2x) . . . . . . for x > 0

PLEASE HELP ME WITH THIS ONE QUESTION
How many combinations with repetition are allowed if n = 6 and r = 3?

A) 27
B) 20
C) 18
D) 56

Answers

Answer:

D. 56

Step-by-step explanation:

The general solution for the number of combinations with repetition is represented by the following expression:

[tex]x = \frac{(n + r - 1)!}{r!\cdot (n-1)!}[/tex] (1)

Where:

[tex]n[/tex] - Total number of elements.

[tex]r[/tex] - Number of the sample.

If we know that [tex]n = 6[/tex] and [tex]r = 3[/tex], then the number of combinations with repetition:

[tex]x = \frac{(6+3-1)!}{3!\cdot (6-1)!}[/tex]

[tex]x = 56[/tex]

Hence, correct answer is D.

HELP!!!!
Car Survey In a survey of 3,200 people who owned a certain type of​ car, 2,080 said they would buy that type of car again. What percent of the people surveyed were satisfied with the​ car?

___% of the people surveyed were satisfied with the car.

Answers

Answer:

65%

Step-by-step explanation:

2080/3200times100%

6 Write 89.4945 correct to (a) nearest whole number, [1] (b) two decimal places. ​

Answers

Answer:

a)89

b)89.45

Step-by-step explanation:

When testing gas pumps for accuracy, fuel-quality enforcement specialists tested pumps andfound that 1304 of them were not pumping accurately (within 3.3 oz when 5 gal ispumped),and 5689 pumps were accurate. Use a 0.01 significance level to test the claimof an industryrepresentative that less than 20% of the pumps are inaccurate.

Answers

Answer:

The p-value of the test statistic from the standard normal table is 0.0017 which is less than the level of significance therefore, the null hypothesis would be rejected and it can be concluded that there is sufficient evidence to support the claim that less than 20% of the pumps are inaccurate.

Step-by-step explanation:

Here, 1304 gas pumps were not pumping accurately and 5689 pumps were accurate.

x = 1304, n = 1304 + 5689 = 6993

The level of significance = 0.01

The sample proportion of pump which is not pumping accurately can be calculated as,

The claim is that the industry representative less than 20% of the pumps are inaccurate.

The hypothesis can be constructed as:

H0: p = 0.20

H1: p < 0.20

The one-sample proportion Z test will be used.

The test statistic value can be obtained as:

[tex]Z=\frac{\hat{p}-P}{\sqrt{\frac{P(1-P))}{n}}}\\\\Z=\frac{0.186-0.20}{6993}\\\\Z=-2.927[/tex]

Line t has an equation of y = -8x + 7. Line u includes the point (-1, 7) and is parallel to line
t. What is the equation of line u?
Write the equation in slope-intercept form. Write the numbers in the equation as proper
fractions, improper fractions, or integers.
Use y=mx+b.
1
2 3 4
5.
12

Answers

Answer:

y = -8x - 1

Step-by-step explanation:

y = mx + b

7 = -8 (-1) + b   Substitute in points for x and y. Substitute -8 for m (parallel)

7 = 8 + b

-1 = b

find slope from the pair of points (2,-2) (-5,4)

Answers

Answer:

-6/7

Step-by-step explanation:

If we have two points, we can find the slope using the slope formula

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

   = ( 4 - -2)/( -5 -2)

   = ( 4+2) /(-5-2)

    = 6/-7

   = -6/7

help? write down the answer with an explanation I give brainiest

Answers

She started with 48 dollars since you divide 6 by 1/2 and get 12 then 12 divided by 1/2 is 24 and 24 divided by 1/2 is 48 , so the answer is 48 dollars

so we'll go backwards.

emily ended with $6.00.

6×2 at the music store = $12

12×2 at the bakery = $24

24 × 2 at the grocery store = $48

she started with a total of $48.00

to check answer:

48 ÷ 2 = 24 at bakery

24 ÷ 2 = 12 at music

12 ÷ 2 =6 at lunch

Solve the inequality.
y-6 < -13
y< 19
O
y<7
y<-7
y < -19

Answers

Answer:

y < -7.

Step-by-step explanation:

y - 6 < -13

Add 6 to both sides:

y - 6 + 6 < -13 + 6

y < -7.

If m and n are two rational numbers, then m+n lies between m and n
2​

Answers

Answer:

19thuuzvdkedhddudhjdhdhfghfidhdhdhfheidhfjr9fddy6gqufgaqgxhrhrydudkydtdffyztstdtiztuytzmyrsyrststststsut0egjjefeigjeojokfzbkehfzifgihrxeudihxizhieg9zfjz9deffejfjiefeihfiefhiefhefiefh3fr3hi3jfhfhfkzdhf2ivuvdfuvuzfecfkfidyfl5a4

The time, t, required to drive a fixed distance varies inversely as the speed, r. It takes 2 hr at a speed of 15 km/h to drive a fixed distance. How long will it take to drive the same distance at a speed of 29 km/h?

The time taken to drive the same distance at a speed of 29km/h is

Answers

Answer:

1.03h

Step-by-step explanation:

S=vt

S= 15km/h*2h

S= 30km

Distance same, S=30km

v= 29km/h

t = 30/29

t = 1.03 h

How do you find the surface area

Answers

Answer:

It depends on what shape you have. Here are some formulas for different shapes.

Step-by-step explanation:

Rectangular prism: 2lw + 2lh + 2wh

Cylinder: 2 pi r² + 2 pi rh

Sphere: 4 pi r²

Cone: pi r² + pi rl

Square-based pyrimid: 1/2lp +B

I hope this helps!

3. Find the length of X (in the picture) plssss I need help.​

Answers

Answer:

imagine the upper triangle as the same as the lower one, but rotated by 180° around the corner point they share, and resized.

the base of the smaller triangle is resized by a factor of 3/4.5, or reduced: 1/1.5

we just take the length from the hypotenuse of the bigger triangle and resize it to, either by multiplying with 1/1.5 or by dividing by 1.5

personally, I find the latter easier.

x = 7.5/1.5 = 5

he speeds (in MPH) of automobiles traveling in a city are given below:
20, 35, 42, 52, 65, 49, 24, 37, 23, 41, 50, 58
The mean speed of the cars is

Answers

Answer:

Mean speed = 41.3 mph

Step-by-step explanation:

Given that,

The speeds of an automobiles are given below:

20, 35, 42, 52, 65, 49, 24, 37, 23, 41, 50, 58

We need to find the mean speed of the cars.

Mean = sum of observations/ no. of observation

[tex]M=\dfrac{20+35+42+52+65+49+24+37+23+41+50+58}{12}\\\\M=41.3[/tex]

So, the mean speed of the cars is equal to 41.3 mph.

Which represents where f(x) = g(x)

Answers

Answer: f(2) = g(2) and f(0) = g(0)

Explanation: The graphs equal the same thing (intercept) at those x values!

PLS HELP ASAP!!!

THANK YOU.

Answers

9514 1404 393

Answer:

rectangular prism: 288 ft³triangular prism: 72 ft³total: 360 ft³

Step-by-step explanation:

The volume of a rectangular prism is given by the formula ...

  V = LWH . . . . . the product of length, width, height

This rectangular prism has a volume of ...

  V = (12 ft)(6 ft)(4 ft) = 288 ft³ . . . . rectangular prism volume

__

The volume of a triangular prism is found from the formula ...

  V = Bh

where B is the area of the triangular base, and h is the height of the prism (distance between the triangular bases). The triangular base area is found from ...

  A = 1/2bh . . . . .where b is the base of the triangle, and h is its height.

Here, we have ...

  B = 1/2(6 ft)(4 ft) = 12 ft²

  V = Bh = (12 ft²)(6 ft) = 72 ft³ . . . . triangular prism volume

__

The total volume of the given geometry is the sum of the volumes of the parts:

  aquarium volume = 288 ft³ +72 ft³ = 360 ft³

Find the probability

Answers

Answer:

[tex]\frac{1}{5}[/tex]

Step-by-step explanation:

Red: 2

Blue: 4

Yellow: 4

[tex]\frac{2}{10}[/tex]

[tex]\frac{2/2}{10/2}=\frac{1}{5}[/tex]

Which statement is true regarding the graphed functions?

Answers

Answer:

I am pretty sure that it's the second one

a bag contains 5white and 3red identical balls.if the balls are drawn at random after the other without replacement. what is the probability that the first red ball is picked at fifth draw​

Answers

Answer:

2/7

Step-by-step explanation:

A bus travels at a constant speed. The following table shows the distance the bus travels (in kilometers) over a period of
time (in hours):
distance (d) 42 252 378
time (9 0.5 3
4.5
a. Use complete sentences to describe the relationship represented in the table.
b. Write an equation using variables that represents the relationship shown in the table.
c. Use your equation to find how far the bus travels in 6 hours.

Answers

Answer:

question is not clear

specify the table

If I have 46 $ and the taxi cab charges 0.60$ plus 7$ fee how far can I ride

Answers

Answer:

65 miles

Step-by-step explanation:

costs = flat fee + cost per mile * miles

46 = 7+ .60m

Subtract 7 from each side

46-7 = 7+.6m-7

39 = .6m

Divide each side by .6

39/.6 = m

65 miles

Solve the compound inequality 7x ≥ –56 and 9x < 54.

Answers

Answer: first one is x≥-8 second one is x<6

Step-by-step explanation: for the first one you divide both sides by 7 and the second won do the same except divide by 9 on each side

Hello,

7x ≥ -56

⇔ 7x / 7 ≥ -56 / 7

⇔ x ≥ -8

S = [-8 ; +∞[

9x < 54

⇔ 9x / 9 < 54 / 9

⇔ x < 6

S = ]-∞ ; 6]

:-)

Wayne is picking out some movies to rent, and he is primarily interested in dramas and horror films. He has narrowed down his selections to 7 dramas and 16 horror films. How many different combinations of 3 movies can he rent if he wants at least two dramas

Answers

Answer:

The number of selections is 49.

Step-by-step explanation:

drama = 7

horror films = 16

Select 3 movies at least two dramas

For 2 drama and 1 horror film

(3 C 2) x (16  C 1) = 48

For 3 drama

(3 C 3) = 1

So, total number of selections is 48 + 1 = 49.  

how do i simplify 81^5 = 3x

Answers

Step-by-step explanation:

81/5=3x

x=81×1/5×3

x=81/15

Need help with this question

Answers

Answer:

cant see it

Step-by-step explanation:

just type it out

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