Simplify. Write each answer in scientific notation

According to the Bureau of Labor Statistics, citizens remain unemployed for an average of 15.9 weeks before finding their next j

Ahat [919]

Complete Question

According to the Bureau of Labor Statistics, citizens remain unemployed for an average of 15.9 weeks before finding their next job (June, 2008). Suppose you want to show that Louisiana has been effective in getting their unemployed back to work sooner. You take a random sample of 50 citizens who were unemployed six months earlier and ask them to report the duration. You find that the average time spent unemployed was 13.4 weeks with a sample standard deviation of the time unemployed is 6.7 weeks.

1 Which of the following statements is the correct alternative hypothesis?

2 The test statistic for testing the hypothesis is

a. -2.64

b. -2.32

c. -2.11

d. -1.28

e. none of these are correct

Answer:

1

The alternative hypothesis $H_a : \mu < 15.9$

2

The test statistics $z = -2.64$

Step-by-step explanation:

From the question we are told that

The population mean value for time citizens remain unemployed is $\mu = 15.9 \ weeks$

The sample size is n = 50

The sample standard deviation is 6.7 weeks.

The sample mean value for time citizens remain unemployed is $\mu = 15.9 \ weeks$

The null hypothesis is $H_o : \mu \ge 15.9$

The alternative hypothesis $H_a : \mu < 15.9$

Generally test statistics is mathematically represented as

$z = \frac{ \= x - \mu }{ \frac{s}{\sqrt{n} } }$

=> $z = \frac{13.4 - 15.9}{\frac{6.7}{\sqrt{50}}}$

=> $z = -2.64$

7 0

3 years ago

A hollow metal sphere has 6 cm inner and 8cm outer radii. The surface charge densities on the exterior surface is +100 nC/m2 and

natulia [17]

Answer:

<h2>Outer Electric Field is 11250 N/C.</h2><h2>Inner Electric Field is -10000 N/C.</h2>

Step-by-step explanation:

First of all, we need to read carefully and analyse the problem. As you can see, is an electrical subject, and it's given surface charge densities and radius.

So, to calculate electric fields, we need to find the proper equation to do so: $E=k\frac{q}{r^{2} }$ ; as you can see, first we need to find the charges.

We can find all charges using the surface charge densities, because it has the next relation: $p=\frac{q}{A}$ ; which indicates that charge density is the amount of charge per area. But, there's a problem, we don't have areas, so we have to calculate them first with this relation: $S=4\pi r^{2}$ ; which gives us the surface of a sphere.