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2 years ago

An arithmetic sequence has a first term of 4 and a common difference of 3. What is the 20th term

Mathematics

1 answer:

tino4ka555 [31]2 years ago

8 0

Answer:

Step-by-step explanation:

aₙ = a₁ + (n - 1)d

aₙ = 4 + (20 - 1)3

aₙ = 4 + (19)3

aₙ = 4 + 57

aₙ = 61

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Last year, Philip Rivers' passing percentage was 66%, which means he completed 66% of his

statuscvo [17]

Answer:

363

Step-by-step explanation:

0.66*550=363

8 0

3 years ago

The sales of a grocery store had an average of $8,000 per day. The store introduced several advertising campaigns in order to in

oksano4ka [1.4K]

Answer:

Null hypothesis: $\mu \leq 8000$

Alternative hypothesis: $\mu > 8000$

$z=\frac{8300-8000}{\frac{1200}{\sqrt{64}}}=2$

$p_v =P(Z>2)=0.0228$

Step-by-step explanation:

1) Data given and notation

$\bar X=8300$ represent the sample mean

$\sigma=1200$ represent the population standard deviation

$n=64$ sample size

$\mu_o =800$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

2) State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is higher than 8000, the system of hypothesis are :

Null hypothesis: $\mu \leq 8000$

Alternative hypothesis: $\mu > 8000$

Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (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".

3) Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{8300-8000}{\frac{1200}{\sqrt{64}}}=2$

4) P-value

Since is a one-side upper test the p value would given by:

$p_v =P(Z>2)=0.0228$

5) Conclusion

If we compare the p value and the significance level assumed, for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the mean is significantly higher than $8000.

4 0

3 years ago

The coordinates of the vertices of a polygon are shown on the grid below

AnnZ [28]

Uhm Where is the grid?

5 0

3 years ago

Paloma Co. has four employees. FICA Social Security taxes are 6.2% of the first $128,400 paid to each employee, and FICA Medicar

Crazy boy [7]

No this is to much work for something that is 5 points to do Na man but I hope this helps you in the future .

8 0

3 years ago

[ Easy Math ] Help me pls

goldfiish [28.3K]

Answer:

1) you're going to have to flip the coins (or fake numbers) for the experimental trials.

2) for the theoretical, there is 1/2 chance for heads or tails with each toss, so you'd expect that out of 10 tosses, 5 heads, 5 tails. out of 100 tosses- 50 heads, 50 tails.

When tossing 2 coins- 1/2×1/2 = 1/4 (25%) chance that 2 heads, 2 tails, or 1 heads & 1 tails. Deviation value comes from after you done your flipping and recorded your data. So if on 100 flips you actually got 50 and 50 (rarely us that exact ;), the deviation from the expected of 50/50 would be 0.00. If however you flipped 100 heads or 100 tails (impossible), then the deviation value would be 1.00.

|(100-50)| ÷ 50 = 50÷50 = 1.00

So usually you may have data like: 47/53 or something a little off than 50/50, making deviation |(47-50)| ÷ 50 = 3÷50 = 0.06.

Now the number of flips is important for the outcome! So if a coin toss if 10 times had 4 heads, 6 tails, the deviation value would be:

|(4-5)| ÷ 5 = 1÷5 = 0.20

So increasing the # flips DECREASES the deviation value!!

Whether it's from 10 to 100, or from 100 to 200. Look at my example of how the 10-flip deviation of 0.20 decreased to 0.06 with 100-flip

7 0

3 years ago