MATHEMATICS COLLEGE

Forty-five CEO’s from the electronics industry were randomly sampled and a 99 % % confidence interval for the average salary of all electronics CEO’s was constructed. The interval was $101,866<μ<$115,016 $101,866<μ<$115,016 To make more useful inferences from the data, it is desired to reduce the width of the confidence interval. What will result in a reduced interval width? Select one: a. Any of these methods will result in a reduced interval width. b. Keep the sample size the same and decrease the confidence level. c. Keep the sample size the same and increase the confidence level. d. Decrease the sample size and keep the same confidence level.

Answers

Answer 1

Answer:

Answer:

b. Keep the sample size the same and decrease the confidence level.

Step-by-step explanation:

We first have to find the critical value of z, which depends of the confidence level.

90% confidence level

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = (1-0.9)/(2) = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$

99% confidence level

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = (1-0.99)/(2) = 0.005$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.005 = 0.995$ , so $z = 2.575$

The width of the interval is:

$W = z*(\sigma)/(√(n))$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

So, as z increses, so does the width. If z decreases, the width decreases. Lower confidence levels have lower values of z.

As n increases, the width decreses.

What will result in a reduced interval width?

b. Keep the sample size the same and decrease the confidence level.

Related Questions

A jar has 4 red marbles 7 blue marbles and 8 yellow marbles what is the probability of randomly selecting a marble and getting a blue marble?Please help!!!!
Find the area:A.16B.64C.256D.none of these
What makes the graph curve upwards or downwards?a nothingb. Md.kPlease select the best answer from the choices provided
Need someone’s help with this please!!!
A commercial jet has been instructed to climb from its present altitude of 6000 feet to a cruising altitude of 30,000 feet. If the plane ascends at a rate of 4000 ft/min, how long will it take to reach its cruising altitude? The plane will take nothing minutes.

Complete the number sentence to solve. Three students share 5 feet of ribbon equally. How many feet of ribbon does each student get? 5 + 3 = Each student's share is 1 feet of ribbon.

Answers

Answer:

The answer is that each student gets 1.666667 feet of ribbon

Step-by-step explanation:

Which situation can be modeled by a function?A. Raquel can spend $15 on 1 shirt, $30 on 2 shirts,or $30 on 3 shirts.

B. Bonnie can spend $10 on a shirt, $20 on 2 shirts, and $20 on 3 shirts.

C. Maria can spend $15 on 1 shirt, $15 on 2 shirts, or $30 on 3 shirts.

D. Natalie can spend $15 on 1 shirt, $30 on 2 shirts, or $45 on 3 shirts.

Answers

The equation is y = 15x , where y is the total cost of the shirt and x is the number of shirts

What is an Equation?

Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.

It demonstrates the equality of the relationship between the expressions printed on the left and right sides.

Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.

Given data ,

Let the equation be represented as A

Now , the value of A is

Substituting the values in the equation , we get

Let the total cost of the shirt be represented as y

Let the number of shirts be represented as x

Now , the cost of 1 shirt = $ 15

The cost of 2 shirts = $ 30

And , the cost of 3 shirts = $ 45

So , the equation will be y = 15x , where x is the number of shirts

Hence , the equation is y = 15x , where y is the total cost of the shirt

To learn more about equations click :

brainly.com/question/19297665

#SPJ2

Answer:

Step-by-step explanation:

the simplest form of this equation would be that (x) is the number of shirts and 15 would be your (y). (1)15=15, (2)15=30 and so on.

HELLLLLLPPPPPPPPO MEEEEEEEEE

Answers

Answer:

Volume = lwh

V = 1.6 x 2.8 x 3.2

V = 14.336

V = 14.3 cubed

Yellow is the right answer.

Round 34.037 to 3 significant figures.
a. 34.04
b. 34
c. 34.037
d. 34.0

Answers

Answer:

My answer to the question is 34.0

What is the result of 72 divided by 12? 6 8 9 12

Answers

Answer:

the answer is 6

Step-by-step explanation:

Answer:

Step-by-step explanation:

Hope this helps!!!!!!

consider the quadratic form q(x,y,z)=11x^2-16xy-y^2+8xz-4yz-4z^2. Find an orthogonal change of variable that eliminates the cross product in q(x,y,z) and express q in the new variables.

Answers

Answer:

$q(x,y,z)=16x^(2)-5y^(2)-5z^(2)$

Step-by-step explanation:

The given quadratic form is of the form

$q(x,y,z)=ax^2+by^2+dxy+exz+fyz$ .

Where $a=11,b=-1,c=-4,d=-16,e=8,f=-4$ .Every quadratic form of this kind can be written as

$q(x,y,z)={\bf x}^(T)A{\bf x}=ax^2+by^2+cz^2+dxy+exz+fyz=\left(\begin{array}{ccc}x&y&z\end{array}\right) \left(\begin{array}{ccc}a&(1)/(2) d&(1)/(2) e\n(1)/(2) d&b&(1)/(2) f\n(1)/(2) e&(1)/(2) f&c\end{array}\right) \left(\begin{array}{c}x&y&z\end{array}\right)$

Observe that $A$ is a symmetric matrix. So $A$ is orthogonally diagonalizable, that is to say, $D=Q^(T)AQ$ where $Q$ is an orthogonal matrix and $D$ is a diagonal matrix.

In our case we have:

$A=\left(\begin{array}{ccc}11&((1)/(2))(-16) &((1)/(2)) (8)\n((1)/(2)) (-16)&(-1)&((1)/(2)) (-4)\n((1)/(2)) (8)&((1)/(2)) (-4)&(-4)\end{array}\right)=\left(\begin{array}{ccc}11&-8 &4\n-8&-1&-2\n4&-2&-4\end{array}\right)$

The eigenvalues of $A$ are $\lambda_(1)=16,\lambda_(2)=-5,\lambda_(3)=-5$ .

Every symmetric matriz is orthogonally diagonalizable. Applying the process of diagonalization by an orthogonal matrix we have that:

$Q=\left(\begin{array}{ccc}(4)/(√(21))&-(1)/(√(17))&(8)/(√(357))\n(-2)/(√(21))&0&\sqrt{(17)/(21)}\n(1)/(√(21))&(4)/(√(17))&(2)/(√(357))\end{array}\right)$

$D=\left(\begin{array}{ccc}16&0&0\n0&-5&0\n0&0&-5\end{array}\right)$

Now, we have to do the change of variables ${\bf x}=Q{\bf y}$ to obtain

$q({\bf x})={\bf x}^(T)A{\bf x}=(Q{\bf y})^(T)AQ{\bf y}={\bf y}^(T)Q^(T)AQ{\bf y}={\bf y}^(T)D{\bf y}=\lambda_(1)y_(1)^(2)+\lambda_(2)y_(2)^(2)+\lambda_(3)y_(3)^(2)=16y_(1)^(2)-5y_(2)^(2)-5y_(3)^2$

Which can be written as:

$q(x,y,z)=16x^(2)-5y^(2)-5z^(2)$

Other Questions

2(x + 25) =100 hellppppppp meee

We can show that ∆ABC is congruent to ∆A′B′C′ by a translation of

The volume of an object is given as a function of time by V = A + B t + C t4 . Find the dimension of the constant C

Tickets for a carnival for a family of 4 costs $28. The ticket includes 1 food item and 3 games.Select ALL true statements below based on this information.