Mike bought a soft drink for 4 dollars and 9 candy bars. He spent a total of 31 dollars. How much did each candy bar cost ?
1 answer:
You might be interested in
Answer:
The degrees of freedom are given by:
Since is a two-sided test the p value would be:
Since the p value is a very low value we have enough evidence to conclude that true mean is significantly different from 1.35 in/year at any significance level commonly used for example ().
Step-by-step explanation:
Data given and notation
represent the sample mean
represent the sample 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 1.35 in/year, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
The statistic is given by:
(1)
Calculate the statistic
We can replace in formula (1) the info given like this:
P-value
The degrees of freedom are given by:
Since is a two-sided test the p value would be:
Since the p value is a very low value we have enough evidence to conclude that true mean is significantly different from 1.35 in/year at any significance level commonly used for example ().
To solve this we are going to use the exponential function: 
where
is the final amount after 
years
is the initial amount
is the decay or grow rate rate in decimal form
is the time in years
Expression A
Since the base (0.95) is less than one, we have a decay rate here.
Now to find the rate, we are going to use the formula: 
*100%
*100%
*100%
5%
We can conclude that expression A decays at a rate of 5% every three months.
Now, to find the initial value of the function, we are going to evaluate the function at
We can conclude that the initial value of expression A is 624.
Expression B
Since the base (1.12) is greater than 1, we have a growth rate here.
To find the rate, we are going to use the same equation as before:
*100%
*100
*100%
*100%
12%
We can conclude that expression B grows at a rate of 12% every 4 months.
Just like before, to find the initial value of the expression, we are going to evaluate it at
The initial value of expression B is 725.
We can conclude that you should select the statements:
- Expression A decays at a rate of 5% every three months, while expression B grows at a rate of 12% every fourth months.
- Expression A has an initial value of 624, while expression B has an initial value of 725.
where
Expression A
Since the base (0.95) is less than one, we have a decay rate here.
Now to find the rate
We can conclude that expression A decays at a rate of 5% every three months.
Now, to find the initial value of the function, we are going to evaluate the function at
We can conclude that the initial value of expression A is 624.
Expression B
Since the base (1.12) is greater than 1, we have a growth rate here.
To find the rate, we are going to use the same equation as before:
We can conclude that expression B grows at a rate of 12% every 4 months.
Just like before, to find the initial value of the expression, we are going to evaluate it at
The initial value of expression B is 725.
We can conclude that you should select the statements:
- Expression A decays at a rate of 5% every three months, while expression B grows at a rate of 12% every fourth months.
- Expression A has an initial value of 624, while expression B has an initial value of 725.