The lcm of a set of numbers is equal to one of the numbers in the set.

We are given that a particular brand of tires claims that its deluxe tire averages at least 50,000 miles before it needs to be replaced. From past studies of this tire, the standard deviation is known to be 8000.

From the 28 tires surveyed, the mean lifespan was 46,500 miles with a standard deviation of 9800 miles.

Let $\mu$ = average miles for deluxe tires

So, Null Hypothesis, $H_0$ : $\mu \geq$ 50,000 miles {means that deluxe tire averages at least 50,000 miles before it needs to be replaced}

Alternate Hypothesis, $H_A$ : $\mu$ < 50,000 miles {means that deluxe tire averages less than 50,000 miles before it needs to be replaced}

The test statistics that will be used here is One-sample z test statistics as we know about population standard deviation;

T.S. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean lifespan = 46,500 miles

$\sigma$ = population standard deviation = 8000 miles

n = sample of tires = 28

So, test statistics = $\frac{46,500-50,000}{\frac{8000}{\sqrt{28} } }$

= -2.315

The value of the test statistics is -2.315.

Now at 5% significance level, the z table gives critical value of -1.6449 for left-tailed test. Since our test statistics is less than the critical value of z as -2.315 < -1.6449, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that deluxe tire averages less than 50,000 miles before it needs to be replaced which means that the claim is not supported.

4 0

3 years ago

PLEASE HELP I'M TIMED

DedPeter [7]

Really hope i'm right

1st row

the first one is length less than 10

one next to it is width greater than 5

next to that is length greater than 10

2nd row

the first one is length greater than 10

one next to that is width less than 5

next to that is width greater than 5

3rd row

first one is width less than 5

and last is length less than 10

4 0

3 years ago

Can i have help on this q plz

lukranit [14]

Answer:

No, they will need an additional £34 to stay the planned 10 nights.

Step-by-step explanation:

Attached screenshot of a spreadsheet.

The cost for 10 nights for the 2 people is £100.

The tent site rental (over 10m^2) for 10 nights is £150.

Savings for the two over the 9 weeks is £216.

They will need an additional £34 to camp as planned.

I suggest fibbing about the extra 0.5m^2 needed for the tent site. That will reduce the bill by £30, so they are only £4 short. Time to make a couple of friends.

3 0

2 years ago