Problem 2: Did the Covid-19 quarantine increase the screen time? On average Canadians spend 3.5 hours on their smartphones per day. However, during the Covid-19 lockdown period a Toronto research base conducted a survey on an SRS of 86 Canadians and found that the average time spent looking at screens is 4.2 hours with a standard deviation of 2.13 hours. A) Determine the population mean, u and the sample mean x-bar. B) Classify the hypotheses test as two-tailed, left-tailed, or right-tailed. Explain your answer. C) Determine the null hypothesis for the hypothesis test. Write out in words and in math symbols.
Addition Rule of Probability
It simply refers to the likelihood of an event taking place whenever the occurrence of an event is uncertain. The probability of a single event can be calculated by dividing the number of successful trials of that event by the total number of trials.
Expected Value
When a large number of trials are performed for any random variable ‘X’, the predicted result is most likely the mean of all the outcomes for the random variable and it is known as expected value also known as expectation. The expected value, also known as the expectation, is denoted by: E(X).
Probability Distributions
Understanding probability is necessary to know the probability distributions. In statistics, probability is how the uncertainty of an event is measured. This event can be anything. The most common examples include tossing a coin, rolling a die, or choosing a card. Each of these events has multiple possibilities. Every such possibility is measured with the help of probability. To be more precise, the probability is used for calculating the occurrence of events that may or may not happen. Probability does not give sure results. Unless the probability of any event is 1, the different outcomes may or may not happen in real life, regardless of how less or how more their probability is.
Basic Probability
The simple definition of probability it is a chance of the occurrence of an event. It is defined in numerical form and the probability value is between 0 to 1. The probability value 0 indicates that there is no chance of that event occurring and the probability value 1 indicates that the event will occur. Sum of the probability value must be 1. The probability value is never a negative number. If it happens, then recheck the calculation.
Can I get some help on problem 2 A-C
Let X be the time spent on smartphones or the screen time
A) Then, the population mean is given to be:
On conducting a survey of 86 candidates, the data for sample is:
n = 86
Sample mean:
B) Since we have to test whether the screen time has increased due to Covid-19 quarantine, it is a right-tailed test as the alternate hypothesis will be that the population mean has increased to be greater than the initial value of 3.5
If the screen time was tested to have decreased due to the quarantine, the hypotheses would have been left-tailed.
Similarly, if the screen time was tested to be different than 3.5 (either increased or decreased) due to the quarantine, the hypotheses would have been two-tailed.
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