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Mathematics

1 answer:

Vanyuwa [196]3 years ago

7 0

I am not sure but I think it’s c

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An automobile manufacturer has given its van a 47.2 miles/gallon (MPG) rating. An independent testing firm has been contracted t

7nadin3 [17]

Answer:

The test statistics is $t = -1.7$

The Null and Alternative hypothesis are

$H_o : \mu = 47.2$ and $H_a : \mu \ne 47.2$

Step-by-step explanation:

From the question we are told that

The population mean is $\mu = 47.2 miles/gallon(MPG)$

The sample size is $n = 250 \ van$

The sample mean is $\= x = 47.0$

The sample standard deviation is $\sigma = 1.9$

The level of significance is $\alpha = 0.02$

Given that the value which the manufacturer gave the automobile is 47.2 and it is believed that this is not correct, then

The Null Hypothesis is

$H_o : \mu = 47.2$

The alternative Hypothesis is

$H_a : \mu \ne 47.2$

The test statistics can be mathematically evaluated as

$t = \frac{\= x- \mu}{\frac{\sigma }{\sqrt{n} } }$

substituting values

$t = \frac{\= 47- 47.2}{\frac{1.9 }{\sqrt{250} } }$

$t = -1.7$

7 0

3 years ago

Rewrite the expression in terms of the given function 1/1-sinx - sinx/1+sinx

Feliz [49]

Your question seems a bit incomplete, but for starters you can write

$\dfrac1{1-\sin x}-\dfrac{\sin x}{1+\sin x}=\dfrac{1+\sin x}{(1-\sin x)(1+\sin x)}-\dfrac{\sin x(1-\sin x)}{(1+\sin x)(1-\sin x)}=\dfrac{1+\sin x-\sin x(1-\sin x)}{(1-\sin x)(1+\sin x)}$

Expanding where necessary, recalling that $(1-\sin x)(1+\sin x)=1-\sin^2x=\cos^2x$ , you have

$\dfrac{1+\sin x-\sin x(1-\sin x)}{(1-\sin x)(1+\sin x)}=\dfrac{1+\sin x-\sin x+\sin^2x}{\cos^2x}=\dfrac{1+\sin^2x}{\cos^2x}$

and you can stop there, or continue to rewrite in terms of the reciprocal functions,

$\dfrac{1+\sin^2x}{\cos^2x}=\sec^2x+\tan^2x$

Now, since $1+\tan^2x=\sec^2x$ , the final form could also take

$\sec^2x+\tan^2x=\sec^2x+(\sec^2x-1)=2\sec^2x-1$

or

$\sec^2x+\tan^2x=(1+\tan^2x)+\tan^2x=1+2\tan^2x$