Answer:
The bottom Right one
Step-by-step explanation:
Answer:

Step-by-step explanation:
We have,
Radius of the circle is 12 cm
Arc length, l = 21 cm
It is required to find the central angle of the circle. The formula for the length of an arc of a circle is :

is central angle

So, the angle at the centre of the circle is
.
Answer:
a) Null Hypothesis: length of each screw is less than 14 centimeters
b) Alternate Hypothesis: length of each screw is equal to or greater than 14 centimeters
Step-by-step explanation:
Complete question
A factory that manufactures screws is performing a quality control experiment. Each object should have a length of no more than 14 centimeters. The factory believes that the length of the screws exceeds this value and measures the length of screws. The sample mean screw length was centimeters. The population standard deviation is known to be centimeters.
1. What is the null hypothesis?
2. What is the alternative hypothesis?
Solution :
The null hypothesis is basically the problem statement that needs to be tested.
Alternate hypothesis is opposite of that of null hypothesis
a) Null Hypothesis: length of each screw is less than 14 centimeters
b) Alternate Hypothesis: length of each screw is equal to or greater than 14 centimeters