A bookbook can be classified as either non dash fictionnon-fiction or fictionfiction. Suppose that 9494% of booksbooks are clas
1 answer:
You might be interested in
Answer:
The 70% mixture makes up 0.7 liters of the solution whereas the 60% mixture makes up 2.8 liters of the solution.
Step-by-step explanation:
Let us have x liters of the .7 mixture and y liters of the .6 mixture.
We want total liters to be 3.5 which means we need x+y=3.5 . I don't like the decimal in the equation so I'm going to multiply both sides by 10: 10x+10y=35
We also need the .7x+.6y=.62(3.5) . I hate the decimal business going on in this question so I'm going to multiply by 1000 which gives 700x+600y=62(35) .
So we have the system
700x+600y=62(35)
10x+10y=35
I'm going to setup this up for linear combination/elimination.
Multiply bottom equation by 60.
700x+600y=62(35)
600x+600y=60(35)
Subtract equations (bottom from top):
(700-600)x+(600-600)y=35(62-60)
Simplify:
100x+0y=35(2)
100x=70
Divide both sides by 100:
x=70/100
x=7/10
Going back to x+y=3.5 along with x=7/10 or .7 liters to find y.
y=3.5-x with x=.7
y=3.5-0.7
y=2.8
The 70% mixture makes up 0.7 liters of the solution whereas the 60% mixture makes up 2.8 liters of the solution.
Pic added.
Another way to do problem:
.7x+.6(3.5-x)=.62(3.5)
Multiply and distribute:
.7x+2.1-.6x=2.17
Combine like terms on left:
.1x+2.1=2.17
Subtract 2.1 on both sides:
.1x=.07
Multiply both sides by 10:
x=0.7 liters
Now the other acid solution is 3.5-0.7 which is 2.8 litera.
Answer:
1. H0: P1 = P2
2. Ha: P1 ≠ P2
3. pooled proportion p = 0.542
4. P-value = 0.0171
5. The null hypothesis failed to be rejected.
At a signficance level of 0.01, there is not enough evidence to support the claim that there is significant difference between the exercise habits of Science majors and Math majors .
6. The 99% confidence interval for the difference between proportions is (-0.012, 0.335).
Step-by-step explanation:
We should perform a hypothesis test on the difference of proportions.
As we want to test if there is significant difference, the hypothesis are:
Null hypothesis: there is no significant difference between the proportions (p1-p2 = 0).
Alternative hypothesis: there is significant difference between the proportions (p1-p2 ≠ 0).
The sample 1 (science), of size n1=135 has a proportion of p1=0.607.
The sample 2 (math), of size n2=92 has a proportion of p2=0.446.
The difference between proportions is (p1-p2)=0.162.
The pooled proportion, needed to calculate the standard error, is:
The estimated standard error of the difference between means is computed using the formula:
Then, we can calculate the z-statistic as:
This test is a two-tailed test, so the P-value for this test is calculated as (using a z-table):
As the P-value (0.0171) is bigger than the significance level (0.01), the effect is not significant.
The null hypothesis failed to be rejected.
At a signficance level of 0.01, there is not enough evidence to support the claim that there is significant difference between the exercise habits of Science majors and Math majors .
We want to calculate the bounds of a 99% confidence interval of the difference between proportions.
For a 99% CI, the critical value for z is z=2.576.
The margin of error is:
Then, the lower and upper bounds of the confidence interval are:
The 99% confidence interval for the difference between proportions is (-0.012, 0.335).