Answer:
NO, as per study, I cant see any other problem than the sample size in the procedure.
From the graph there is a slight quadratic relationship between temperature and number of O-rings.
As in the graph, we can see that above 50°F but below 55°F number of O-rings in 3 but after 55°F as temperature goes on increasing the number of O-rings decreases and remains constant up to 70°F and above 70°F the number of O-rings increases to 2. Hence, we can say that there is a relationship between temperature and number of O-rings.
If we want to fit a linear regression through these seven observations, the slope would be positive as linear regression line passes through the average.
Looking at the relationship, slope must be significantly different from zero as there is a relationship between two variables, where as slope significantly zero implies no relationship. However, we have only seven points so drawing a conclusion is difficult as the nature of the relationship is not clearly visualized by this graph.
2.1a - 0.4b - 1.2 is the correct answer

The denominator of a fraction can't be equal to 0.

The function is undefined at x=-1, x=2, x=4, because for these values the denominator of the function would equal 0, and it's impossible to divide by 0.
Edward is correct.
We have been given that the weight of an object on the mars varies directly as the weight of the object on earth.
Let y be weight of an object on Mars and x be weight of an object on Earth.

We have been given that the weight of an object on Mars is 34 pounds and weight of the same object on Earth is 90 pounds.
Putting the given values in equation we get

Therefore, our equation now becomes

Now we have been given that the weight of an object on Earth is 135 pounds and we have to find the weight of the same object on Mars,
We have been given that 
Putting the given values in our equation we get

Therefore weight of the object on Mars will be 51 pounds.