21. A data professional working for a smartphone manufacturer is analyzing sample data on the weight of a specific smartphone. The data follows a normal distribution, with a mean weight of 150g and a standard deviation of 10g. According to the empirical rule, approximately what percentage of the data values lie between 140g and 160g?
- 99.7%
- 50%
- 95%
- 68%
22. If a data value has a z-score of 0, what does the value equal?
- The mode
- The mean
- The median
- The standard deviation
23. A data professional is analyzing sales data for a retail store. The data follows a normal distribution. What Python function can they use to compute z-scores for the data?
- median.zscore()
- mean.zscore()
- stats.zscore()
- normal.zscore()
24. If all outcomes of an event are equally likely, how is its probability calculated?
- Divide the total number of possible outcomes by the number of desired outcomes.
- Divide the total number of certain outcomes by the number of possible outcomes.
- Divide the number of desired outcomes by the total number of possible outcomes.
- Divide the total number of possible outcomes by the number of certain outcomes.
25. A coin is tossed twice. To calculate the probability of getting two heads in a row, which of the following equations should be used?
- ½ – ½
- ½ ÷ ½
- ½ + ½
- ½ * ½
26. Which of the following events are mutually exclusive? Select all that apply.
- Getting a 4 on a first die roll and a 6 on a second die roll
- Getting heads and tails on the same coin toss
- Getting heads on a first coin toss and tails on a second coin toss
- Getting a 4 and a 6 on the same die roll
27. Which of the following are examples of discrete random variables? Select all that apply.
- The number of radios produced in a factory each day
- The time it takes to drive from one city to another city
- The number of rooms in a hotel
- The length of an airplane
28. The Poisson distribution can model which of the following kinds of data? Select all that apply.
- The number of visitors per day on a website
- The number of heads in 10 fair coin tosses
- The number of customers per week at a retail store
- The number of calls per hour at a call center
Shuffle Q/A 3
29. A data professional working for a smartphone manufacturer is analyzing sample data on the weight of a specific smartphone. The data follows a normal distribution, with a mean weight of 150g and a standard deviation of 10g. What data value lies 3 standard deviations below the mean?
- 130g
- 160g
- 180g
- 120g
30. The mean and the standard deviation of a standard normal distribution always equal what values?
- Mean = 1; standard deviation = 2
- Mean = 2; standard deviation = 1
- Mean = 0; standard deviation = 2
- Mean = 0; standard deviation = 1