If the sales tax rate in California is 7.25% then how much would you pay in Los Angeles for a pair of shoes that cost 39.00?

A particular brand of tires claims that its deluxe tire averages at least 50,000 miles before it needs to be replaced. From past

Minchanka [31]

<h2><u>Answer with explanation</u>:</h2>

Let $\mu$ be the distance traveled by deluxe tire .

As per given , we have

Null hypothesis : $H_0 : \mu \geq50000$

Alternative hypothesis : $H_a : \mu$

Since $H_a$ is left-tailed and population standard deviation is known, thus we should perform left-tailed z-test.

Test statistic : $z=\dfrac{\overlien{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}$

where, n= sample size

$\overline{x}$ = sample mean

$\mu$ = Population mean

$s$ =sample standard deviation

For $n= 31,\ \sigma=8000,\ \overline{x}=46,800\ \&\ s=46,800$ , we have

$z=\dfrac{46800-50000}{\dfrac{8000}{\sqrt{31}}}=-2.23$

By using z-value table,

P-value for left tailed test : P(z≤-2.23)=1-P(z<2.23) [∵P(Z≤-z)=1-P(Z≤z)]

=1-0.9871=0.0129

Decision : Since p value (0.0129) < significance level (0.05), so we reject the null hypothesis .

[We reject the null hypothesis when p-value is less than the significance level .]

Conclusion : We do not have enough evidence at 0.05 significance level to support the claim that t its deluxe tire averages at least 50,000 miles before it needs to be replaced.

4 0

3 years ago

−x+10=−5<br><br> Please help and include step by step.

sergey [27]

Step by Step:

Step 1.) Subract 10 from both sides.

Step 2.) Divide each side by one

answer: x=15

3 0

3 years ago

Read 2 more answers

Lake has a total of $10,000 to invest in two accounts. One account earns 1% simple interest, and the other earns 10% simple inte

Elza [17]

Answer:

$8000 at 1%
$2000 at 10%

Step-by-step explanation:

It often works well to let a variable represent the amount invested at the higher rate. Then an equation can be written relating amounts invested to the total interest earned.

__

<h3>setup</h3>

Let x represent the amount invested at 10%. Then 10000-x is the amount invested at 1%. The total interest earned is ...

0.10x +0.01(10000 -x) = 280

<h3>solution</h3>

Simplifying gives ...

0.09x +100 = 280

0.09x = 180 . . . . . . . subtract 100

x = 2000 . . . . . . divide by 0.09

10000 -x = 8000 . . . . amount invested at 1%

$8000 should be invested in the 1% account

$2000 should be invested in the 10% account