Answer:
a = 1
Step-by-step explanation:
x = 8
3x - y = 9
3(8) - y = 9
24 - y = 9
-y = 9 - 24
-y = -15
y = 15
ax + y = 23
a(8) + 15 = 23
8a = 23 - 15
8a = 8
a = 8/8
a = 1
Answer:
The number is <u>less than</u> 3.5
Step-by-step explanation:
Let us break up and convert each individual phrase into its equivalent in an equation.
"Three time" is
"The difference of a number and three" is (3-x)
"Is greater than" is >
"The number decreased by five" is (x-5)
We can now put all of these parts together to get our equation
Now, we can simplify this and solve for x
Answer:
Step-by-step explanation:
Data given and notation
represent the sample mean
represent the sample standard deviation
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 true mean is different from 7.1 ppm, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:
(1)
t-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:
rs 38.
Step-by-step explanation:
Total cost of the 80 books = 80*30 = rs 2400.
He had 60 books to sell and made a 5% loss.
Thus his income from these books was 2400 - 0.05*2400 = rs 2280.
So the selling price of each book was 2280 / 60 = rs 38.
Answer:
1/5
Step-by-step explanation:
To simplify, we can first divide the top and bottom by 10:
2/10
Then by 2:
1/5