To find the angle use arc tan (-5/-7) which simplifies tips arctan(5/7). arc tan is tan to the power -1, which is also called inverse tan. The heading of the angle, if you drew this out on a graph your angle would be in the third quadrant and therefore the heading is south of west.
Answer:
H0 ; μ ≤ 4 pCi/L
Ha ; μ > 4 pCi/L
The null hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is less than or equal to the safe level of 4pCi/L
H0 ; μ ≤ 4 pCi/L
The alternative hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L.
Ha ; μ > 4 pCi/L
Step-by-step explanation:
The null hypothesis (H0) tries to show that no significant variation exists between variables or that a single variable is no different than its mean. While an alternative Hypothesis (Ha) attempt to prove that a new theory is true rather than the old one. That a variable is significantly different from the mean.
The null hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is less than or equal to the safe level of 4pCi/L
H0 ; μ ≤ 4 pCi/L
The alternative hypothesis is that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L.
Ha ; μ > 4 pCi/L
The answer is 25.
-1/5n = -5
-n = -25
n = 25