Answer:
84
Step-by-step explanation:
Total students he surveyed: 27
Amount that found it something OTHER than easy: 14 (11 moderate + 3 difficult)
This means that 
found it something other than easy
Multiply that by 162 to find the proportion for the larger population:
162 * (14/27), and we get 84.
Answer:
No, because all the expected frequencies must be higher than 5.
Step-by-step explanation:
The chi-square test might be performed in those situations in which we need to know if a series of observations adjust or not to a theoretical function, such as the normal, Poisson, or binomial.
The chi-square test does not require the number of files to coincide with the number of columns in the table. It does not establish any restriction about the number of modalities per variable. However, the expected frequencies or counts should not be less than five.
In the exposed example, this unique rule is not accomplished, so the chi-square test can not be performed.
Answer:
The shadow length is 125 inches.
Step-by-step explanation:
The triangle that the sun's rays and the fence post form is shown in the figure.
From trigonometry we know that 
is the ratio of the opposite <em>(72-in fence)</em> to the adjacent side 
of the triangle <em>(the shadow length): </em>
<em />
<em />
since
<em />
<em />
we have
<em />
<em />
solving for we get:
Hence, the length of the shadow to the nearest inch is 125 inches.
