Answer:
yes
Step-by-step explanation:
Answer:the price now is $128
Step-by-step explanation:
you can get this by dividing the cost by the percentage it has risen by. For example: 120 / 15 = 8 and then you add 8 to the initial price
Answer:
both negative 1 over two
Step-by-step explanation:
X>-63/43 let me know if you need an explanation ❤️
Answer:
The test is left - tailed
We cannot reject the organization's claim ( its cheapest screens will truly last less than 2.8 years)
Step-by-step explanation:
Sample size, n = 61
Sample mean, ![\bar{X} = 2.4](https://tex.z-dn.net/?f=%5Cbar%7BX%7D%20%3D%202.4)
Standard deviation, ![\sigma = 0.88](https://tex.z-dn.net/?f=%5Csigma%20%3D%200.88)
Significance level, α=0.02
Null hypothesis, ![H_{o} : \mu = 2.8](https://tex.z-dn.net/?f=H_%7Bo%7D%20%3A%20%5Cmu%20%3D%202.8)
Alternative hypothesis, ![H_{a} : \mu < 2.8](https://tex.z-dn.net/?f=H_%7Ba%7D%20%3A%20%5Cmu%20%3C%202.8)
It is clearly seen from the alternative hypothesis, that it is a left tailed test. It is not tailed towards the two directions.
Calculate the test statistic:
![Z = \frac{\bar{X} - \mu}{\sigma/\sqrt{n} } \\Z = \frac{2.4 - 2.8}{0.88/\sqrt{61} }\\Z = - 3.55](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7B%5Cbar%7BX%7D%20-%20%5Cmu%7D%7B%5Csigma%2F%5Csqrt%7Bn%7D%20%7D%20%5C%5CZ%20%3D%20%5Cfrac%7B2.4%20-%202.8%7D%7B0.88%2F%5Csqrt%7B61%7D%20%7D%5C%5CZ%20%3D%20-%203.55)
Calculate the P-value:
P(Z < -3.35) = 0.0002
Since (p-value = 0.0002) < (α=0.02), the null hypothesis is rejected.
It can therefore be concluded that the mean of the cheapest screen is less than 2.8 years. i.e. the cheapest screen will last less than 2.8 years