PLEASE HELP ASAP!!! solve for the given variable and show your work. 3a-12b=30. solve for b.
1 answer:
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Answer:
Step-by-step explanation:
<u>Step 1: Set x to -2 </u>
Answer:
For this case we have the following expression:
Since the denominator is equal, then we can add the numerator.
We have then:
Adding similar terms we have:
Rewriting we have:
Doing common factor in the numerator we have:
Factoring the denominator we have:
Canceling similar terms we have:
Answer:
The simplest form of the expression has 7 in the numerator and m+4 in the denominator.
Since the denominator is equal, then we can add the numerator.
We have then:
Adding similar terms we have:
Rewriting we have:
Doing common factor in the numerator we have:
Factoring the denominator we have:
Canceling similar terms we have:
Answer:
The simplest form of the expression has 7 in the numerator and m+4 in the denominator.
Answer:
The null and alternative hypothesis can be written as:
Step-by-step explanation:
This is a hypothesis test for the difference between proportions.
The claim is that the proportion of 18- to 34-year-old Americans that own a cell phone is less than the proportion of 35- to 49-year-old Americans.
This claim will be reflected in the alternnative hypothesis, that will state that the population proportion 1 (18 to 34) is significantly smaller than the population proportion 2 (35 to 49).
On the contrary, the null hypothesis will state that the population proportion 1 is ot significantly smaller than the population proportion 2.
Then, the null and alternative hypothesis can be written as:
The significance level is assumed to be 0.05.
The sample 1, of size n1=200 has a proportion of p1=0.63.
The sample 2, of size n2=175 has a proportion of p2=0.68.
The difference between proportions is (p1-p2)=-0.05.
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 left-tailed test, so the P-value for this test is calculated as (using a z-table):
As the P-value (0.1554) is bigger than the significance level (0.05), the effect is not significant.
The null hypothesis failed to be rejected.
There is not enough evidence to support the claim that the proportion of 18- to 34-year-old Americans that own a cell phone is less than the proportion of 35- to 49-year-old Americans.