Write the fraction or mixed number as a decimal

In 1990, the mean duration of long-distance telephone calls originating in one town was 7.2 minutes. A long-distance telephone c

scoundrel [369]

Answer:

We know that In 1990, the mean duration of long-distance telephone calls originating in one town was 7.2 minutes. And we want to test if the mean duration of long-distance phone calls has changed from the 1990 mean of 7.2 minutes (alternative hypothesis) and the complement rule would represent the null hypothesis.

The correct system of hypothesis are:

Null hypothesis: $\mu =7.2$

Alternative hypothesis: $\mu \neq 7.2$

So then the best option for this case would be:

H0: μ = 7.2 minutes Ha: μ ≠ 7.2 minutes

Step-by-step explanation:

We know that In 1990, the mean duration of long-distance telephone calls originating in one town was 7.2 minutes. And we want to test if the mean duration of long-distance phone calls has changed from the 1990 mean of 7.2 minutes (alternative hypothesis) and the complement rule would represent the null hypothesis.

The correct system of hypothesis are:

Null hypothesis: $\mu =7.2$

Alternative hypothesis: $\mu \neq 7.2$

So then the best option for this case would be:

H0: μ = 7.2 minutes Ha: μ ≠ 7.2 minutes

And in order to test the hypothesis we can use a one sample t test or z test depending if we know the population deviation or not

4 0

3 years ago

Use the zero product property to find the solutions to the equation x^2-15x-100=0

7nadin3 [17]

Answer:

$x = 20$ or $x = -5$