2. In a random sample of 87 college students, the average number of GroupMe messages handled in
one day is 49. The 95% confidence interval for the mean number of messages handled by students
daily is given as 47 to 51.
a. What is the population standard deviation of the sample?
b. If the number of samples were doubled, by what factor would the confidence interval change
(keeping the same confidence level?)

Answers

Answer 1

We have that the population standard deviation and  confidence interval is mathematically given as

SD=1

W = 2.8284

Standard deviation and the new width

a) Generally, normal distribution 95% of the values lies within 2 standard deviations from the mean.

Therefore, we have here:

2*2SD = 51 - 47

2*2SD

SD=1

Hence, the standard deviation is

SD=1

b)

Where,the margin of error is inversely proportional to the square root of sample size.

1 / sqrt{2}

Hence, the new width is

1 / sqrt{2}[tex]1 \ sqrt{2}[/tex]

W = 2.8284

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Related Questions

Challenge An arts academy requires there to be 4 teachers for every 76 students and 3 tutors for
every 36 students. How many students does the academy have per teacher? Per tutor? How many
tutors does the academy need if it has 108 students? The academy has 10 students per teacher.

Answers

Answer:

12. 5

11.

10

10

15. 7

14. 11

2

=

16

16

18. 3

+

11

17

3

4

co

loo

8

Step-by-step explanation:

12. 5

11.

10

10

15. 7

14. 11

John bought new headphones originally listed for $ 80.99 . They are \(35\%)| off. Which equation can be used to find the amount John will save?

Answers

Answer:

$28.35

Step-by-step explanation:

The headphones are $80.99 and are 35% off. To find the amount he will save, change the 35% to a decimal by moving it two times to the left, which is 0.35. Multiply 80.99 and 0.35 to get 28.3465. Round to get $28.35.

How many 1/4
gram dosages of medication can be obtained from a container
holding 3/8
gram of the medication?

Answers

The quantity of dosages of medication that can be obtained from the container is 1.5 dosages.

Given the following data:

Mass of medication = [tex]\frac{1}{4}[/tex] grams.Mass of container = [tex]\frac{3}{8}[/tex] grams.

To calculate the quantity of these dosages of medication that can be obtained from the container:

How to calculate the dosages.

In this exercise, you're required to determine the amount of dosages of medication can be obtained from the container. Thus, we would divide the given mass of container by the mass of medication as follows:

[tex]Quantity = \frac{\frac{3}{8}}{\frac{1}{4}}[/tex]

Simplifying further, we have:

[tex]Quantity = \frac{3}{8} \times 4\\\\Quantity = \frac{12}{8} \\\\Quantity = \frac{3}{2}[/tex]

Quantity = 1.5 dosages.

Read more on word problems here: brainly.com/question/13170908

Abigail and her mom want to make matching pairs of polka-dotted pajama pants. So, they go to the craft store to pick out fabric. Abigail needs 4 feet of fabric for her pajamas, and her mom needs 6 feet of fabric. But, the store only sells fabric by the yard. If they buy 4 yards of fabric, how many feet will be leftover?

Answers

Answer: 2 feet

Explanation: A yard is 3 feet.
4 feet for Abigail and 6 for her mother makes 10 feet in total.
4 yards x 3 (to convert to feet, every yard is 3 feet, so you multiply) equals 12 feet.
12 - 10 is 2.

Luke can paint 91 portraits in 7 weeks.
How many portraits can Luke paint in 4 weeks?
MA
portraits
As

Answers

91 divided by 7 is 13. so he can paint 13 in 1 week. 13 x 4 equals 52 so he can paint 52 portraits in 4 weeks.

he can paint ( 4 / 7 ) * 91 paintings in 4 weeks

4 / 7 = 0.57142857142

0.57142857142 * 91 = 52 paintings in 4 weeks

A number p has exactly 12 factors. Two of the factors are 4 and 15. Find the value of p

Answers

Answer:

p=60

Step-by-step explanation:

it is divisible by

1

60

20

3

4

15

2

30

12

5

6

10

The quotient of two numbers is 3 their difference is 8 what are the two numbers

Answers

Answer:

x = 12, y = 4

Step-by-step explanation:

x / y = 3

x - y = 8

Or

12 / 4 = 3

12 - 3 = 8

If you roll a 6-sided die, what is
the probability that you will get a
number greater than 5?

Answers

1/6 (16.667%)

I looked it up

For each expression, write an equivalent expression that uses only addition.
20−9+8−7
4x−7y−5z+6
-3x−8y−4−87z

Answers

Answer:

1) 28 - 16 = 12

2) 4x + 6 -7y -5z

3) -3x -8y - 4 - 87z

These were all mostly simplified already.

Hope this helps!

calculate without using calculate
3(-2+4)​

Answers

Answer: 6

Step-by-step explanation:

Parentheses- (-2+4)= (2)

Multiply 3(2)= 6

factor
2ay³/-4a²b
PLS HELP ME BRAINLIEST IF CORRECT

Answers

Answer:

the answer is y³/-2ab :)

The circumference of a circle is 10.4mm.
Find the length of the diameter.
Give your answer rounded to 3 SF.

Answers

Answer:

diameter: 3.31 mm

Explanation:

circumference of circle → πd

using the formula:

10.4 = πd

d = 10.4/π

d = 3.31 mm

Answer:

diameter = 3.31 mm (3 sf)

Step-by-step explanation:

Diameter of a circle (d) = 2r  (where r is the radius)Circumference of a circle = 2[tex]\pi[/tex]r  (where r is the radius)
⇒ circumference = [tex]\pi[/tex]d

Given:

circumference = 10.4 mm

⇒ [tex]\pi[/tex]d = 10.4

⇒ d = 10.4 ÷ [tex]\pi[/tex] = 3.31 mm (3 sf)

expressions that are equivalent to 3x+6y+3

Answers

Answer:

3(x+2y+1)

3x+6x+3

Step-by-step explanation:

anyone knows the answer?

Answers

9.75x > 195

X=20

195/9.75=20, so he must work more than 20 hours.

Carolyn swim 35 laps in 1/2 hour. How far will she swim in 4 hours? Please help.

Answers

70 laps in 40 hours


1/2+1/2=4

35+35=70
I think
70 hours the other person is right tho

Solve the following equation:
3x = -12
a.
b.
X = 2
x = -2
No real solutions
X= 2
C.
d.

Answers

Answer:

x = -4

Step-by-step explanation:

3x=-12

Using the division property of equality, we can divide both sides by 3 to isolate x...

x=-12/3

x = -4


I need help please can you explain it please ​

Answers

first it yo mama - clothes = yo mama nakey

Suppose y varies directly with x. If y = 3 when x = 2, find y when x = 3.
A *9/2
B *2/3
C *3/2
D *2/9​

Answers

Answer:

9/2

Step-by-step explanation:

Direct variation is

y = kx where k is the constant of variation

Substitute into the equation to find k

y=3 and x=2

3 = k*2

Solve for k

3/2 = k

y = 3/2 x

We know x =3

y = 3/2 * 3

y = 9/2

Answer:

A

Step-by-step explanation:

given y varies directly with x then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition y = 3 when x = 2 , then

3 = 2x ( divide both sides by 2 )

[tex]\frac{3}{2}[/tex] = k

y = [tex]\frac{3}{2}[/tex] x ← equation of variation

When x = 3 , then

y = [tex]\frac{3}{2}[/tex] × 3 = [tex]\frac{9}{2}[/tex] → A

One fourth of what number is 5/6

Answers

Answer:

20/6 or 10/3 or 3 1/3

Step-by-step explanation:

Answer:

10/3 = 3 1/3

Step-by-step explanation:

If 5/6 is one fourth (1/4) of a number,

multiply 5/6 by 4 to find the number:

5/6 x 4 = 10/3 = 3 1/3

*PLEAS E HELP* *IRRELEVANT ANSWERS WILL BE REPORTED*

A scuba diver is 30 feet below the surface of the water 10 seconds after he entered the water and 120 feet below the surface after 40 seconds. What is the scuba diver's rate of change (include the units)?
Find slope(Rate of Change)

Answers

Answer:

3 feet  per second

Step-by-step explanation:

The rate of change is:

m = the change in depth / the change in time =      (120 - 30) / (40 - 10) =      90 / 30 =      3 feet/second

Take 2 points

(10,30)(40,120)

Rate of change=Slope:-

[tex]\\ \rm\hookrightarrow m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]

[tex]\\ \rm\hookrightarrow m=\dfrac{120-30}{40-10}[/tex]

[tex]\\ \rm\hookrightarrow m=\dfrac{90}{30}[/tex]

[tex]\\ \rm\hookrightarrow m=3ft/s[/tex]

850 tickets were sold for a game for a total of $1,487.50. If adult tickets sold for $2.00 and children's tickets sold
for $1.50, how many of each kind of ticket were sold?
They sold_____
adult tickets and_____
children's tickets.

Answers

425 adult tickets and 425 children’s tickets

10=8x^2+2x in standard form with the steps

Answers

Answer:

8x=10

Step-by-step explanation:

hope helps

What is the value of a?

A. 42.6
B. 31.6
C. 26.6

Answers

Answer:31.6

Step-by-step explanation: i did the test

Layla made chili for a football party. She started making the chili at 3:45 P.M. It took 40 minutes to prepare and assemble the ingredients. Then, the chili had to simmer for 45 minutes. What time was the chili ready?

Answers

Answer:

5:10 P.M

Step-by-step explanation:

3:45 P.M + 0hrs 40 min = 4:25 P.M

4:25 P.M + 0hrs 45 min = 5:10 P.M

The chili was ready at 5:10 P.M.

(-5x2 – 43 – 1) +(-4x2 – 4x)

Answers

Answer:

−9x 2 -44-4x

Step-by-step explanation:

1 Simplifica  -5{x}^{2}-43-1−5x

2

−43−1  a  -5{x}^{2}-44−5x

2

−44.

-5{x}^{2}-44-4{x}^{2}-4x

−5x

2

−44−4x

2

−4x

2 Colecciona los términos semejantes.

(-5{x}^{2}-4{x}^{2})-44-4x

(−5x

2

−4x

2

)−44−4x

3 Simplifica.

-9{x}^{2}-44-4x

−9x

2

−44−4x

listo  espero te halla ayudado

Triangle BAC and Triangle EDF are similar. What is the length of DF?

Answers

Check the picture below.

Solve for m. 34m>−12 m>−16 m<−16 m>−9 m<−9

Answers

Answer:

-17m/-6 , 4m/3

Step-by-step explanation:

Im not sure what the question is regarding but if its what im doing in school now that is the answer

Evaluate. Express your answer to the nearest tenth, if necessary.

a) 5.3 ÷ (−8.4)

b) −0.25 ÷ (−0.031)

c) −5.3 + 2.4[7.8 + (−8.3)]

d) 4.2 − 5.6 ÷ (−2.8) − 0.9


~giving brainliest!~

Answers

Answer is C but I’ll double check just in case because my math is kind of off today

An 8 ft length of 4 inch wide crown molding costs $14. how much will it cost to buy 40 ft of crown molding?

Answers

Answer:

$98

Step-by-step explanation:

Hope this helps

Answer:

17.50

Step-by-step explanation:

8 times 4 = 32

32=$14

32/14= 40/x

x= 17.50

How to find the median of 30 37 8

Answers

Answer:

to find the median, divide the odd number by 2 and round it up

for even numbers, only divide by 2.

Average the numbers with the number in the next highest position.

You have a median.

In this case, the median is 30.

The median of the numbers 30, 37, and 8 is 30.

To find the median of a set of numbers, you first need to arrange the numbers in either ascending or descending order and then determine the middle value.

Given the numbers: 30, 37, 8

Arrange the numbers in ascending order:

8, 30, 37

Determine the middle value:

Since there are three numbers, the middle value is the second number, which is 30.

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#SPJ3

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