Given:
μ = 25 mpg, the population mean
σ = 2 mpg, the population standard deviation

If we select n samples for evaluation, we should calculate z-scores that are based on the standard error of the mean.
That is,
$z= \frac{x-\mu}{\sigma / \sqrt{n} }$

The random variable is x = 24 mpg.

Part (i): n = 1
σ/√n = 2
z = (24 -25)/2 = -0.5
From standard tables,
P(x < 24) = 0.3085

Part (ii): n = 4
σ/√n = 1
z = (24 -25)/1 = -1
P(x < 24) = 0.1587

Part (iii): n=16
σ/√n = 0.5
z = (24 - 25)/0.5 = -2
P(x < 24) = 0.0228

Explanation:
The larger the sample size, the smaller the standard deviation.
Therefore when n increases, we are getting a result which is closer to that of the true mean.

6 0

3 years ago

Write a recursive formula for the sequence 7, 4, 1, –2, –5, .... Then find the next term. (1 point) an = an–1 – 3, where a1 = –8

Anvisha [2.4K]

4 = 7 - 3

1 = 4 - 3

-2 = 1 - 3

-5 = -2 - 3

=> An = A (n-1) - 3, where A1 = 7

The next term is A6 = A5 - 3 = - 5 - 3 = - 8

So the answer is the fourth option.

3 0

2 years ago

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