X=2 so the value of x+5 is 7
Answer:
Step-by-step explanation:
Data given and notation
represent the sample mean
represent the population standard deviation for the sample
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
t would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if the mean is lower than 800, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
If we analyze the size for the sample is > 30 and we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:
(1)
z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
Calculate the statistic
We can replace in formula (1) the info given like this:
Answer:
A. 3.85
Step-by-step explanation:
- If 11 oranges cost $2.35, we could calculate the cost of each of these oranges, simply dividing the total cost ($2.35) between the amount of oranges bougth (11). This will give us the cost of a single orange, that is, the unitary cost=
. - Then, if we want to know the cost of 18 oranges, we just have to multiply the cost of a single orange (0.21) by 18: 0.21x18 = 2.85