Answer:
Continuous random variables: c and e
Discrete random variables: a, b, d
Step-by-step explanation:
We have to identify whether the random variable is discrete or continuous.
- A discrete variable is a variable whose value is obtained by counting.
- A continuous random variable X takes all values in a given interval of numbers.
- Thus, a continuous variable can have values in decimals but a discrete random variable cannot take values in decimals.
a. The number of statistics students now reading a book.
Discrete random variable since number of students cannot take decimal values.
b. The number of textbook authors now sitting at a computer.
Discrete random variable since number of textbooks cannot be expressed in decimals but counted.
c. The exact time it takes to evaluate 27 plus 72.
It is a continuous random variable as it may take all values within an interval of time.
d. The number of free dash throw attempts before the first shot is made.
It is a discrete random variable since the number of throws can always be whole number.
e. The time it takes to fly from City Upper A to City Upper B.
Time is a continuous random variable.
If someone covers 4 laps in 12 minutes, he would be able to cover 1 lap in 3 minutes if that was the question. The question isn’t really clear.
Answer:
The sample size is 4
Step-by-step explanation:
Null hypothesis: The mean is 2
Alternate hypothesis: The mean is less than 2
Mean = 3
sd = sqrt(variance) = sqrt(4) = 2
At 95% confidence level, t-value is 1.960
Assuming the lower bound of the mean is 1.04
Lower bound = mean - (t×sd/√n)
1.04 = 3 - (1.96×2/√n)
3.92/√n = 3 - 1.04
3.92/√n = 1.96
√n = 3.92/1.96
√n = 2
n = 2^2
n = 4
The equarion to this problem is 30 + 100 + 50x = x