Answer:
Let's start by breaking down the problem.
This is how it should look. ↓
÷
⇒
⇒
What does that <em>x</em> mean? <em>x</em> is just a substituted value for the first 2 equations.
Now, we can solve.
÷
Add 3
Now, multiply 6 times 5 squared. What does 5 squared mean? 5 squared is just 5 times itself once. You most likely want to solve 5 squared before multiplying.
And now for the last step, multiply 25 times 6
With that information, the problem is solved! Your answer is 150
Step-by-step explanation:
the answer is on the pic above
Answer:
a)
The null hypothesis is
The alternative hypothesis is
b-1) The value of the test statistic is t = 1.86.
b-2) The p-value is of 0.0348.
Step-by-step explanation:
Question a:
Test if the battery life is more than twice of 5 hours:
Twice of 5 hours = 5*2 = 10 hours.
At the null hypothesis, we test if the battery life is of 10 hours or less, than is:
At the alternative hypothesis, we test if the battery life is of more than 10 hours, that is:
b-1. Calculate the value of the test statistic.
The test statistic is:
We have the standard deviation for the sample, so the t-distribution is used to solve this question
In which X is the sample mean, is the value tested at the null hypothesis, s is the standard deviation and n is the size of the sample.
10 is tested at the null hypothesis:
This means that
In order to test the claim, a researcher samples 45 units of the new phone and finds that the sample battery life averages 10.5 hours with a sample standard deviation of 1.8 hours.
This means that
Then
The value of the test statistic is t = 1.86.
b-2. Find the p-value.
Testing if the mean is more than a value, so a right-tailed test.
Sample of 45, so 45 - 1 = 44 degrees of freedom.
Test statistic t = 1.86.
Using a t-distribution calculator, the p-value is of 0.0348.