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jarptica [38.1K]

3 years ago

12

Nora bought a car last year so that she could drive to work after school. She spent $250 last year for gas. This year she spent

$295. Disregarding other factors, what is the inflation rate? 18% 19% 20% 21%

1 answer:

frosja888 [35]3 years ago

6 0

Answer:

here,

money spent in 1st year =$250

money spent in 2nd year=$295

total inflated amount=$295- $250

=$45

Then,

inflation rate= ($45/ $250)×100%

=18%

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Where p' is the proportion of the sample, n is the size of the sample, p is the proportion of the population and $z_{\alpha/2}$ is the z-value that let a probability of $\alpha/2$ on the right tail.

Then, a 98% confidence interval for the percentage of all males who identify themselves as the primary grocery shopper can be calculated replacing p' by 0.52, n by 2400, $\alpha$ by 0.02 and $z_{\alpha/2}$ by 2.33

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With a confidence level of 98%, the percentage of all males who identify themselves as the primary grocery shopper are between 0.4962 and 0.5438.

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Finally, the level of significance is the probability to reject the null hypothesis given that the null hypothesis is true. It is also the complement of the level of confidence. So, if we create a 98% confidence interval, the level of confidence $1-\alpha$ is equal to 98%

It means the the level of significance $\alpha$ is:

$\alpha =1-0.98=0.02$

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