This makes no sense can someone please explain.

"Use the following information to answer the question. The mean age of lead actresses from the top ten grossing movies of 2010 w

julia-pushkina [17]

Answer:

a) 10.6; 48.7; within

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 29.6

Standard deviation = 6.35

"According to the Empirical Rule, the ages of nearly all lead actresses will be between______________and_____________ years.

Nearly all(99.7%) will be within 3 standard deviations from the mean.

So from 29.6 - 3*6.35 = 10.6 years to 29.6 + 3*6.35 = 48.7 years.

Anna was 11-years old, so she was within this range.

So the correct answer is

a) 10.6; 48.7; within

7 0

3 years ago

A boat traveled downstream a distance of 90 miles and then came right back. If the speed of the current was 8mph and the total t

Fiesta28 [93]

Recall your d = rt, distance = rate * time.

keeping in mind that, the distance upstream as well as downstream is the same, 90 miles, let's say the boat has a speed rate of "b", thus when the boat was going upstream, it really wasn't going "b" fast, it was going "b - 8", because the 8mph speed of the current is subtracting from it. Likewise, when the boat was going downstream, it wasn't going "b" fast either, because the current was adding to it, since it was going with the current, then it was really going "b + 8" fast.

now, let's notice the trip took a total of 6 hours, thus, if the trip downstream took say "t" hours, then the trip upstream took the slack from 6 and "t", that is, it took "6 - t" hours.

$\bf \begin{array}{lccclll}
&\stackrel{miles}{distance}&\stackrel{mph}{rate}&\stackrel{hours}{time}\\
&------&------&------\\
Downstream&90&b+8&t\\
Upstream&90&b-8&6-t
\end{array}
\\\\\\
\begin{cases}
90=t(b+8)\implies \cfrac{90}{b+8}=\boxed{t}\\\\
90=(6-t)(b-8)\\
----------\\
90=\left( 6-\boxed{\cfrac{90}{b+8}} \right)(b-8)
\end{cases}$

$\bf 90=\left( \cfrac{6b+48-90}{b+8} \right)(b-8)\implies 90=\left( \cfrac{6b-42}{b+8} \right)(b-8)
\\\\\\
90=\cfrac{(6b-42)(b-8)}{b+8}\implies 90(b+8)=(6b-42)(b-8)
\\\\\\
90b+720=6b^2-48b-42b+336\implies 0=6b^2-180b-384
\\\\\\
0=b^2-30b-64\implies 0=(b-32)(b+2)\implies b=
\begin{cases}
\boxed{32}\\
-2
\end{cases}$

since the rate of speed wouldn't be a negative unit, then is not -2.

5 0

3 years ago

say you need to land in Eugene Oregon by 1 p.m. the flight is 2750 miles long and the plane moves at a speed of 550 miles per ho

astra-53 [7]

Yes, I believe you will make it by 12pm

5 0

3 years ago

I need help and i have to show my work

jek_recluse [69]

Answer:

5.8x2.4=13.92

Step-by-step explanation:

if you put the two halves of a triangle like this together it makes a square then you times the length and width together and thats your triangle area

3 0

2 years ago

Explain how using the formula for simple interest can help you in solving word problems.

Zarrin [17]

You can probably search it up it should be easy to find

6 0

3 years ago