The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $\frac{\sigma}{\sqrt{n}}$ .

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 98.6, \sigma = 0.62, n = 106, s = \frac{0.62}{\sqrt{106}} = 0.06$

Find the probability of getting a mean temperature of 98.2 degrees F or lower.

This is the pvalue of Z when X = 98.2. So

$Z = \frac{X - \mu}{s}$

$Z = \frac{98.2 - 98.6}{0.06}$

$Z = -6.67$

$Z = -6.67$ has a pvalue of 0.

So there is a 0% probability of getting a mean temperature of 98.2 degrees F or lower.

8 0

2 years ago

A square is folded into half to form a rectangle. the perimeter of the rectangle is 36cm. calculate the area of a square

zhannawk [14.2K]

Answer:

Let the measure of each side of the square be " x " cm.

then ,

area of square = x²

After we folded the square into a rectangle ,

length of rectangle = x

breadth of rectangle = x/2

perimeter of rectangle = 36 cm

$x + \frac{x}{2} + x + \frac{x}{2} = 36 \\ \\ \frac{2x + x + 2x + x}{2} = 36 \\ \\ \frac{6x}{2} = 36 \\ \\ 6x = 36 \times 2 \\ \\ 6x = 72 \\ \\ 6x = \cancel{\frac{72}{6} } = 12cm$

hence ,

side of square = 12 cm

therefore ,

area of square = 12 × 12 = 144 cm²

hope helpful~

8 0

2 years ago