Based on a sample of 100 employees a 95% confidence interval is calculated for the mean age of all employees at a large firm. The interval is (34.5 years, 47.2 years).
A. What was the sample mean?
B. Find the margin of error?
C. Find the critical value tc for:
a. a 90% confidence level when the sample size is 22.
b. an 80% confidence level when the sample size is 49.

Answers

Answer 1

Answer:

a

[tex]\= x = 40.85[/tex]

b

[tex]E = 5.85[/tex]

Ca  

   [tex]t_c =  2.08 [/tex]

Cb

   [tex] t_c  =   1.282 [/tex]

Explanation:

From the question we are told that

     The sample size is n  =  100

     The upper limit of the 95% confidence interval is  b =  47.2 years

     The lower limit of the 95% confidence interval is   a =  34.5 years

Generally the sample mean is mathematically represented as

         [tex]\= x = \frac{a + b }{2}[/tex]

=>    [tex]\= x = \frac{47.2 + 34.5 }{2}[/tex]

=>    [tex]\= x = 40.85[/tex]

Generally the margin of error is mathematically represented as

         [tex]E = \frac{b- a }{ 2}[/tex]

=>      [tex]E = \frac{47.2- 34.5 }{ 2}[/tex]

=>      [tex]E = 5.85[/tex]

Considering question C a  

From the question we are told the confidence level is  90% , hence the level of significance is    

      [tex]\alpha = (100 - 90 ) \%[/tex]

=>   [tex]\alpha = 0.10[/tex]

The  sample size is  n =  22

Given that the sample size is not sufficient enough i.e [tex]n < 30[/tex] we will make use of the student t distribution table  

Generally the degree of freedom is mathematically represented as

           [tex]df = n- 1[/tex]

=>        [tex]df = 22 - 1[/tex]

=>        [tex]df = 21[/tex]

Generally from the student  t  distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] at a degree of freedom  of  21 is  

   [tex]t_c =t_{\frac{\alpha }{2} ,  21  } =  2.08 [/tex]

Considering question C b

From the question we are told the confidence level is  80% , hence the level of significance is    

      [tex]\alpha = (100 - 80 ) \%[/tex]

=>   [tex]\alpha = 0.20[/tex]

Generally from the normal distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] is  

   [tex] t_c  =Z_{\frac{\alpha }{2} } =  1.282 [/tex]


Related Questions

Solve for x in each of the following diagrams. ​

Answers

In the left one x equals 12.9 and on the right one x equals 11


By the Exterior Angle Theorem, which of the following is a true statement?

Answers

Answer:

2nd option is the correct answer

Step-by-step explanation:

[tex]m \angle 1 > m \angle 3 \: \& \: m \angle 1 > m \angle 7 \\ [/tex]

According to the Exterior Angle Theorem, the true statement should be considered as the option b.

What is an Exterior Angle Theorem?

The exterior angle theorem defined that at the time when a triangle's side should be extended, the resultant exterior angle formed should be equivalent to the sum of the measures of the two opposite interior angles of the triangle.

So based on this, we can say that the option b is correct.

learn more about an angle here: https://brainly.com/question/6150811

A and B are independent events.
P(A) = 0.6
P(B) = 0.4
What is P(AB)?
O A. 0.24
O B. 0.6
O C. 0.4
D. Not enough information

Answers

Answer:

Not enough information

In a recent year, 6% of cars sold had a manual transmission. A random sample of college students who owned cars revealed the following: out of 124 cars, 29 had manual transmissions. Estimate the proportion of college students who drive cars with manual transmissions with 90% confidence.

Answers

Answer:

The  estimate the proportion of college students who drive cars with manual transmissions with 90% confidence is  

      [tex]0.171 <  p <  0.297 [/tex]  

Step-by-step explanation:

From the question we are told that

    The sample size is  n  =  124

    The population proportion p =  0.06

     The number of cars with manual transmissions is  k =  29

From the question we are told the confidence level is  90% , hence the level of significance is    

      [tex]\alpha = (100 - 90 ) \%[/tex]

=>   [tex]\alpha = 0.10[/tex]

Generally the sample proportion is mathematically represented as

       [tex]\^ p = \frac{ 29 }{124 }[/tex]

=>   [tex]\^ p = 0.234[/tex]

Generally from the normal distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] is  

   [tex]Z_{\frac{\alpha }{2} } =  1.645 [/tex]  

Generally the margin of error is mathematically represented as  

     [tex]E =  Z_{\frac{\alpha }{2} } * \sqrt{\frac{\^ p (1- \^ p)}{n} } [/tex]

=>   [tex]E =   1.645  * \sqrt{\frac{0.234 (1- 0.234 )}{124} } [/tex]

=>   [tex]E =  0.063  [/tex]

Generally 95% confidence interval is mathematically represented as  

      [tex]\^ p -E <  p <  \^ p +E[/tex]

=>  [tex]0.234  - 0.063  <  p <  0.234  + 0.063 [/tex]

=>  [tex]0.171 <  p <  0.297 [/tex]  

How many ways are there to rearrange the letters ALIVE in such a way that the word EVIL is not contained in the resulting word

Answers

Answer: 118 combinations.

Step-by-step explanation:

In ALIVE we have 5 letters, rearranging it we have the possible options of:

5 options for the first letter.

4 options for the second letter, as one was already chosen for the first one

3 options for the third letter, as 2 were already chosen.

2 options for the fourth letter.

1 option for the last letter.

The total number of combinations will be equal to the product of the numbers of options for each letter, then we have:

5*4*3*2*1 = 120 combinations.

And the combinations where the word EVIL is formed are:

AEVIL

EVILA

2 combinations, then the total number of combinations such that the word evil is not formed are:

120 - 2 = 118 combinations.

if f(x) = x^2 + x , find f(-3) a)-12 b)3 c)6

Answers

C is the answer
(-3)^2=9
9+(-3)=6

Choose the equation that represents the asymptote of the graph f(x) = 2^x +3.

y = 0
y = 3
x = 0
x = 3​

Answers

Answer:

x = 0

Step-by-step explanation:

The horizontal asymptote occurs at x = 0, Hence the equation that represents the asymptote of the graph is at x = 0

f(x) = 2^x +3.

0 = 2^x +3.

2^x +3. = 0

2^x = -3

log 2^ x = log(-3)

x log2 = log(-3)

x = log(-3)/log 2

Hence the required function is when x = 0

16) The expression 100 + 5n can be used to find the total price for students to take a field trip to the
science museum. If n represents the number of students, determine the cost for 120 students(n) to
Visit the science museum.
A. $225
B.$105
C. $600
D. $700

Answers

The answer to this question is D

What is 1/32 as a decimal

Answers

Answer:

0.03125

Hope this helps! :)

0.03125 is the answer :) hope it helped

Black friday sale on TVs were 50 in tv for $148.00 or 65 in for $199.00 which is the better buy this is not worth a grade just some understanding​

Answers

Answer:

i personally think the 65 in. one

Step-by-step explanation:

Are the equation linear or nonlinear?​

Answers

Answer:

Results below

Step-by-step explanation:

Equation of the line

A straight line can be written in the form:

y = ax + b

Where a and b are constants and x is the independent variable.

The essential condition for an equation to be linear is that the x must be powered to the exponent 1, which is usually not written.

From the equations presented in the table:

[tex]y = x^1+2[/tex] is linear because the exponent of the x is 1

y = 5(x+2) = 5x + 10 is linear with a=5 and b=10.

y = x is linear with a=1 and b=0

[tex]y = x^2+1[/tex] is not linear because the exponent of x is 2

[tex]y = x(x) = x^2[/tex] is not linear because the exponent of x is 2

The table below summarizes the results

Can someone help me on these questions?

Answers

Me not good on math matics I sorry hybrid

Answer:

I can give you a few of them, sorry

Step-by-step explanation:

5) obtuse 6)straight 7)right 9) 24°

Elvira makes money to buy decorations for the cafeteria by selling little bags of chips in the snack bar. If each bag costs $0.35 and she can sell the bag for $0.90, how many bags must she sell to earn at least $200.

Answers

Answer:

Step-by-step explanation:

.90-.35=.55

200/.55=364 bags i think

Elvira sells a total of 364 bags to earn a profit of $200 and this can be determined by using the unitary methods.

Given :

Elvira makes money to buy decorations for the cafeteria by selling little bags of chips in the snack bar. If each bag costs $0.35 and she can sell the bag for $0.90.Total profit earn = $200

The following steps can be used to determine the total number of bags she sells to earn the profit of $200:

Step 1 - First find the total profit she earns to sell one bag.

= 0.90 - 0.35

= $0.55

Step 2 - Now, using the unitary method find the total number of bags she sells to earn a profit of $200 If she earns a profit of $0.55 to sell one bag.

[tex]=\dfrac{200}{0.55}[/tex]

= 363.63 [tex]\approx[/tex] 364 bags

She sells a total of 364 bags to earn a profit of $200.

For more information, refer to the link given below:

https://brainly.com/question/23423168

using the order of operations, what should be done first to evaluate 8² + 10 (-5) (3) - 5?
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B. Divide 10 by -5.
C. Add 6 and 10.
D. Evaluate 8².​

Answers

Answer:

D

Step-by-step explanation:

Who is good at math?

Answers

Answer:

me depending on what kind of math it is

Step-by-step explanation:

A glider flies 8 miles south from the airport and then 15miles east. Then it flies in a straight line back to. What was the distance of the glider’s last trip back to the airport?

Answers

17 miles
Hope this helps!!

Let tk be the number of ways to choose k beads from a drawer that contains 10 red beads, 8 blue beads, and 11 green beads. Find the generating function for the sequence {tk} 29 k = 0. Do not find a formula for tk.

Answers

Answer:

[tex]\mathbf{G(x) = (1 + x)^{29}}[/tex]

Step-by-step explanation:

From the given information;

The total number of beads  = 10 + 8 + 11 = 29

To choose k beads out 29 beads, let assume that [tex]t_k[/tex] be the no. such that:

[tex]t_k = ( ^{29}_{k}) \ \ \ where; k =0,1,2,3,....,29[/tex]

The sequence [tex]\{ t_k\}^{29}_{k=0} = (^{29}_{k})[/tex]

The generating function for [tex]\{ a_k \}^n_{k=0}[/tex] is:

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[tex]G(x) = \sum \limits ^{n}_{k=0} \ a_k x^k[/tex]

For the sequence above;

[tex]G(x) = \sum \limits ^{29}_{k =0 } (^{29}_{k}) x^k[/tex]

By applying binomial series [tex](1+x)^n = \sum \limits ^n_{k=0} ( ^n_k) x^k[/tex]

Thus:

[tex]\mathbf{G(x) = (1 + x)^{29}}[/tex]

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Answers

Answer:

5/12

Step-by-step explanation:

15 to 36 can also be written as 15/36.

Divide by common values to simplify.

15÷3/36÷3

5/12

Best of Luck!

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Step-by-step explanation:

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Answers

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Step-by-step explanation:

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Step-by-step explanation:

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