-3b-12=-7b Is the solution positive or negative? I need help solving this.

The population of a small town is 40,740. It's population falls by 8% per year. How many years later will the population be 14,5

Mashutka [201]

Answer:

0.9101523758 ≈ 1 year

Step-by-step explanation:

The population of a small town is 40,740.

Its population falls by 8% per year.

Given: Compound interest Amount (A) = P( 1 + $\frac{r}{n}$ $)^{nt}$

14,550 = 40,740(1 + $\frac{-8}{100 * 1}$ $)^{t*1}$

14,550 = (40,740 - 3259.2 $)^{t}$

14,550 = (37,480.8 $)^{t}$

t * log 37,480.8 = log 14,550

t = $\frac{ log 14,550}{log 37,480.8}$ = 0.9101523758 ≈ 1 year

6 0

3 years ago

Heated-treated parts are specified to have a hardness of at least 45 (lower specification limit). Any parts that are below 45 ar

Nataly_w [17]

Answer:

$P(X$

And we can find this probability using the normal standard table or excel and we got:

$P(z$

The figure shows the calculation for this case.

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the hardness of a population, and for this case we know the distribution for X is given by:

$X \sim N(48.5,2)$