What is the distance between -2/3 and 4/3 on a number line?

It is claimed that automobiles are driven on average more than 20,000 kilometers per year. To test this claim, 100 randomly sele

kow [346]

Answer:

$t=\frac{23500-20000}{\frac{3900}{\sqrt{100}}}=8.974$

$p_v =P(t_{99}>8.974)=9.43x10^{-15}$

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we to reject the null hypothesis, and the actual mean is significantly higher than 20000.

Step-by-step explanation:

1) Data given and notation

$\bar X=23500$ represent the sample mean

$s=3900$ represent the sample standard deviation

$n=100$ sample size

$\mu_o =2000$ represent the value that we want to test

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

t would represent the statistic (variable of interest)

$p_v$ 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 determine if the true mean is higher than 20000, the system of hypothesis would be:

Null hypothesis: $\mu \leq 2000$

Alternative hypothesis: $\mu > 2000$

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (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:

$t=\frac{23500-20000}{\frac{3900}{\sqrt{100}}}=8.974$

Calculate the P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=100-1=99$

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

$p_v =P(t_{99}>8.974)=9.43x10^{-15}$

Conclusion

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we to reject the null hypothesis, and the actual mean is significantly higher than 20000.

8 0

3 years ago

Miyuki can type 135 words in 3 minutes.How many words can she expect to type in 8 minutes?

Alekssandra [29.7K]

135 / 3 is 45 and 45 x 8 is 360 so she can type 360 words in 8 minutes.

5 0

3 years ago

Read 2 more answers

A worker can assemble 3 shelf units each hour. During the fifth hour of the shift, there were 115 shelf units in the warehouse.

nasty-shy [4]

A worker can assemble 3 shelf units each hr. During the 5th hr...so the shift has been going on for 5 hrs...at 3 units per hr = (3 * 5) = 15 units assembled during the shift....and if there was 115 units in the warehouse, then that means before the shift, there were (115 - 15) = 100 units assembled <=

4 0

3 years ago

PLEASE HELP<br> ANSWER SERIOUSLY

alex41 [277]

Answer:

raise a product to a power.

you first simplify the parenthesis in the numerator by raising 2 by the power of three and multiplying the exponents.

i suck at explaining, but after the first step the expression looks like:

$(\frac{8r^{6}t^{3} }{4t^{2} })^{2}$

Step-by-step explanation:

5 0

3 years ago

Evaluate the following expression:<br>p/-3 + (-8)= -8

aalyn [17]

P/-3+(-8)=-8
p/-3-8=-8
Add 8 to each side
p/-3-8+8=-8+8
p/-3=0
Multiply both side by 3
p/-3(3)=0(3)
p=0
Check:
p/-3+(-8)=-8
Substitute p with 0
0/-3+(-8)=-8
0-8=-8
-8=-8. As a result, p=0. Hope it help!

7 0

3 years ago