Answer:
It will take 12 hours
Step-by-step explanation:
Distance equals rate times time
d = rt
We know the distance and the rate
240 = 12 * t
Divide each side by 12
240/12 = 12t/12
20 = t
It will take 12 hours
Answer:
Step-by-step explanation: 1/9X ⅝ + (½)³ = 0.19
Answer:
31 aces
Step-by-step explanation:
To find the number of aces you would expect, take the probability of an aces and multiply by the number of tries
1/13 * 400 =30.76923
Rounding up, approximately 31 aces
We need to find out how many adults must the brand manager survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage.
From the given data we know that our confidence level is 90%. From Standard Normal Table we know that the critical level at 90% confidence level is 1.645. In other words, .
We also know that E=5% or E=0.05
Also, since, is not given, we will assume that =0.5. This is because, the formula that we use will have in the expression and that will be maximum only when =0.5. (For any other value of , we will get a value less than 0.25. For example if, is 0.4, then and thus, .).
We will now use the formula
We will now substitute all the data that we have and we will get
which can approximated to n=271.
So, the brand manager needs a sample size of 271
Answer:
The value of the test statistic is
Step-by-step explanation:
The null hypothesis is:
The alternate hypotesis is:
Our test statistic is:
In which X is the sample mean, is the value tested at the null hypothesis, is the standard deviation and n is the size of the sample.
In this problem, we have that:
Then
The value of the test statistic is