Two fifths of the children in the nursery were boys. What was the ratio of boys to girls in the nursery?

A gallon of purple paint covers 400 ft2. How

xxMikexx [17]

You seem to have forgotten the size of the wall, but imaginging the average size of a building i think it would take about 2-3 gallons

6 0

2 years ago

A culture of the bacterium Salmonella enteritidis initially contains 50 cells. When introduced into a nutrient broth, the cultur

photoshop1234 [79]

Answer:

The expression for the number of bacteria after t hours is $P(t) = 50e^{0.2922t}$

Step-by-step explanation:

When introduced into a nutrient broth, the culture grows at a rate proportional to its size.

This means that the size of the population, after t hours, is modeled by the following differential equation:

$\frac{dP}{dt} = rP$

In which R is the growth rate.

The solution of this differential equation is:

$P(t) = P(0)e^{rt}$

In which P(0) is the initial population.

A culture of the bacterium Salmonella enteritidis initially contains 50 cells.

This means that $P(0) = 50$ , and so:

$P(t) = P(0)e^{rt}$

$P(t) = 50e^{rt}$

After 1.5 hours, the population has increased to 775.

This means that $P(1.5) = 775$ . We use this to find r. So

$P(t) = P(0)e^{rt}$

$500e^{1.5r} = 775$

$e^{1.5r} = \frac{775}{500}$

$\ln{e^{1.5r}} = \ln{\frac{775}{500}}$

$1.5r = \ln{\frac{775}{500}}$

$r = \frac{\ln{\frac{775}{500}}}{1.5}$

$r = 0.2922$

The expression is:

$P(t) = 50e^{rt}$

$P(t) = 50e^{0.2922t}$

The expression for the number of bacteria after t hours is $P(t) = 50e^{0.2922t}$

6 0

3 years ago

Find the unit price if a dozen apples cost $4.80

mixas84 [53]

Answer:

0.40 cens

Step-by-step explanation:

7 0

3 years ago

For A = {a,b}, determine A x P(A).

alex41 [277]

Answer:

Since A={a,b}, then $P(A)=\{\emptyset, \{a,b\}, \{a\}, \{b\}\}$ . Remember that the Cartesian Product of two sets A, B is defined by

$A\times B=\{(x,y): x\in A \text{ and } y\in B\}$ . Then

$A\times P(A)=\{(a,\emptyset),(a,\{a,b\}),(a,\{a\}), (a,\{b\}), (b,\emptyset),(b,\{a,b\}),(b,\{a\}), (b,\{b\})\}$

6 0

3 years ago

27. In constructing a confidence interval estimate of the population mean you decide to select 49 random observations to get you

Alika [10]

Answer:

1) a.) Your confidence interval estimate is narrower

2) c.) The width of a confidence interval estimate for a proportion will be narrower for 90% confidence level than for a 95% confidence level

Step-by-step explanation:

Confidence Interval can be stated as M±ME where

M is the sample mean

ME is the margin of error

Margin of Error determines the range of the confidence interval around the mean.

Margin of error (ME) of the mean can be calculated using the formula

ME= $\frac{z*s}{\sqrt{N} }$ where

z is the corresponding statistic in the given confidence level

s is the standard deviation of the sample(or the population if it is known)

N is the sample size

From the formula we can reach the following conclusions:

As N increases, ME decreases.

as confidence level increases, corresponding statistic increases, and thus margin of error increases.

Since your sample size (49) is bigger than your friend's (36), your confidence interval is narrower, because margin of error is narrower.

Since the confidence level 90% has smaller statistic than the confidence level 95%, its confidence interval is narrower.

That is, we can estimate <em>narrower</em> confidence intervals with less confidence.

8 0

3 years ago