For the first digit you have 10 options (0..9).
For each next digit you can't choose the same digit, so you have 9 options.

So number of combinations is 10*9*9*9*9 = <span>65610</span>

4 0

3 years ago

In 2008, data from the Center for Disease Control revealed that 28.5% of all male teenagers, aged 18-19 and attending U.S. colle

m_a_m_a [10]

Answer:

a) H0 : u = 28.5%

H1 : u < 28.5%

b) critical value = - 1.645

c) test statistic Z= - 1.41

d) Fail to reject H0

e) There is not enough evidence to support the professor's claim.

Step-by-step explanation:

Given:

P = 28.5% ≈ 0.285

X = 210

n = 800

$p' = \frac{X}{n} = \frac{210}{800} = 0.2625$

Level of significance = 0.05

a) The null and alternative hypotheses are:

H0 : u = 28.5%

H1 : u < 28.5%

b) Given a 0.05 significance level.

This is a left tailed test.

The critical value =

$-Z_0.05 = -1.645$

The critical value = -1.645

c) Calculating the test statistic, we have:

$Z = \frac{p' - P}{\sqrt{\frac{P(1-P)}{n}}}$

$Z = \frac{0.2625 - 0.285}{\sqrt{\frac{28.5(1-28.5)}{800}}}$

Z = -1.41

d) Decision:

We fail to reject null hypothesis H0, since Z = -1.41 is not in the rejection region, <1.645

e) There is not enough evidence to support the professor's claim that the proportion of obese male teenagers decreased.

5 0

3 years ago