Which is greatest to least the square root of 99, pie or 9.8 repeating

A researcher is concerned about the impact of students working while they are enrolled in classes, and she likes to know if stud

8_murik_8 [283]

Answer:

(a) Point estimate = 7.10

(b) The critical value is 1.960

(c) Margin of error = 0.800

(d) Confidence Interval = (6.3, 7.9)

(e) We are 90% confident that the average number of hours worked by the students is between 6.3 and 7.9

Step-by-step explanation:

Given

$\bar x = 7.10$ -- sample mean

$\sigma=5$ --- sample standard deviation

$n = 150$ --- samples

Solving (a): The point estimate

The sample mean can be used as the point estimate.

Hence, the point estimate is 7.10

Solving (b): The critical value

We have:

$CI = 90\%$ --- the confidence interval

Calculate the $\alpha$ level

$\alpha = 1 - CI$

$\alpha = 1 - 90\%$

$\alpha = 1 - 0.90$

$\alpha = 0.10$

Divide by 2

$\frac{\alpha}{2} = 0.10/2$

$\frac{\alpha}{2} = 0.05$

Subtract from 1

$1 - \frac{\alpha}{2} = 1 - 0.05$

$1 - \frac{\alpha}{2} = 0.95$

From the z table. the critical value for $1 - \frac{\alpha}{2} = 0.95$ is:

$z = 1.960$

Solving (c): Margin of error

This is calculated as:

$E = z * \frac{\sigma}{\sqrt n}$

$E = 1.960 * \frac{5}{\sqrt {150}}$

$E = 1.960 * \frac{5}{12.25}$

$E = \frac{1.960 *5}{12.25}$

$E = \frac{9.80}{12.25}$

$E = 0.800$

Solving (d): The confidence interval

This is calculated as:

$CI = (\bar x - E, \bar x + E)$

$CI = (7.10 - 0.800, 7.10 + 0.800)$

$CI = (6.3, 7.9)$

Solving (d): The conclusion

We are 90% confident that the average number of hours worked by the students is between 6.3 and 7.9

6 0

2 years ago

The telephone company offers two billing plans for local calls. Plan 1 charges $ per month for unlimited calls and Plan 2 charg

vazorg [7]

Mark brainliest pls :)

a.
38<14+0.05x
24<0.05x
x>480
b. When the number of calls per month is greater than 480, then Plan 1 is more economical. Example: If the number of calls is greater than 480 say 500, then charges in plan 2 will be $39, but Plan 1 is more economical and charges will be $38.

5 0

10 months ago

An item costs $430 before tax, and the sales tax is $25.80.

bekas [8.4K]

Answer:

Step-by-step explanation:

if the item is 430, and the sales tax is 25.80

we can find how much is 1%

430/100=4.30

25.80/4.30=6

the sales tax is 6%

8 0

3 years ago

Tom is the deli manager at a grocery store. He needs to schedule employees to staff the deli department at least 260 person-hour

Finger [1]

The expression that could best describe the statement would be " 40 n + 20 $\geq$ 260.

3 0

3 years ago

Read 2 more answers

Apply the junction rule to the junction labeled with the number 1 (at the bottom of the resistor of resistance R2R2R_2). Answer

Ira Lisetskai [31]

Answer:

-I₁ + I₂ + I₃ = 0

I₁ = I₂ + I₃

Step-by-step explanation:

The image of the circuit is obtained online and attached to the question.

The junction rule is essentially a law of conservation of current (charges). It applies to electrical circuits at steady state.

It explains that the for any given junction (node in an electrical circuit), the sum of current entering the junction is equal to the sum of current leaving the junction. That is, the net sum of current at any junction is zero.

Current entering a junction is assigned a positive sign and that leaving the junction is assigned a negative sign.

Σ I = 0

From the image of the circuit attached, I₁ is leaving the junction labelled number 1 and I₂ and I₃ are entering the junction.

Hence,

-I₁ + I₂ + I₃ = 0

I₁ = I₂ + I₃

Hope this Helps!!!

5 0

3 years ago