Rewrite this equation in Ax+By=C form.

The school wishes to purchase 2500 pens and have discovered that 3 stores sell the same model pen.Which store has the best buy ?

8_murik_8 [283]

$Store\ A: \frac{0.5}{15}=0.0333\ cents\ per\ pen \\ \\ Store\ B: \frac{1.7}{50}=0.034\ cents\ per\ pen \\ \\ Store\ C: \frac{0.9}{30} =0.03\ cents\ per\ pen \\ \\ Store\ C\ is\ the\ cheapest.$

7 0

3 years ago

andrezito [222]

Answer:

a) 0.27% probability that the mean is less than 1995 milliliters.

b) 2002.3 milliliters or more will occur only 10% of the time for the sample of 100 bottles.

Step-by-step explanation:

To solve this problem, it is important to understand the normal probability distribution and the central limit theorem

Normal probability distribution

Problems of normally distributed samples are 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.

Central Limit theorem

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 $s = \frac{\sigma}{\sqrt{n}}$