Answer:
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
That is z with a pvalue of 
, so Z = 1.28.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 7.6 - 0.1 = 7.5
The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Answer:
The volcanoes are formed adjacent to a convergent plate boundary, in which the denser plate subducts under a less denser plate. These subducting plates undergoes partial melting at greater depths and the magma is forced to rise up towards the over-riding plate, resulting in the formation of the volcano and chains of volcanoes.
These volcanoes when undergoes eruptions, releases various types of gases. They are such as the Carbon dioxide (CO₂), Water vapor (H₂O), Sulfur dioxide (SO₂), Hydrogen sulfide (H₂S) and Carbon monoxide (CO).
These gases are harmful to the atmosphere as it creases the green house effect thereby increasing the earth's global temperature.
d. you add up all the sides. opposite sides are equal. the answer is d. 36
