Answer:
the common ratio is 0.98.
Step-by-step explanation:
A fish population in a lake decreases by 2% each year. We are asked to find the common ratio.
The decrease of population of fish 2% annually means the population becomes next year 100% - 2% = 98%
Therefore, the common ratio would be 98%. Upon converting 98 percent to a decimal we will get,
98% =
Therefore, the common ratio or decay factor is 0.98.
Answer:
The value of the test statistic is z = -0.877.
Step-by-step explanation:
Testing the difference in mean time spent on housework between husbands and wives.
At the null hypothesis, we test if there is no difference, that is, the subtraction of the means is 0:
At the alternate hypothesis, we test if there is a difference, that is, the subtraction of the means is different from 0.
The test statistic is:
In which X is the sample mean, is the value tested at the null hypothesis, and s is the standard error.
0 is tested at the null hypothesis:
This means that
For the wives the mean was 7 hours/week and for the husbands the mean was 4.5 hours/week. The standard deviation of the differences in time spent on house work was 2.85.
This means that
What is the value of the test statistic for testing the difference in mean time spent on housework between husbands and wives?
The value of the test statistic is z = -0.877.