Answer:
D=-4<0, the equation has no real solutions, it has two imaginary solutions.
Step-by-step explanation:
The quadratic equation has coefficients
a=1,
b=4,
c=5.
The discriminant D is the expression
Hence,
Since the discriminant is negative, the equation has no real solutions, it has two imaginary solutions.
Answer:
a) The expected number of smokers in a random sample of 140 students from this university is 16.8 smokers.
b) No, it is unlikely that smoking habits and waking up early to go to the gym on Saturday are independent.
Step-by-step explanation:
To calculate the expected numbers of smokers in a sample with size n=140 and proportion p=12%, we use the expected value of the binomial distribution:
The expected number of smokers in a random sample of 140 students from this university is 16.8 smokers.
If we take a sample at the opening of the gym, the sample is not expected to be representative of the population of the students. Most of the students that go to the gym usually have healthy habits, so the proportions of smokers is expected to be lower than the average of the university population.