50% of the apartments in a certain building have windows and hardwood floors. 25% of the apartments without windows have hardwoo
1 answer:
Answer:E 83
Step-by-step explanation:
50% of the apartment in a certain building have windows and hardwood floors.
25% of the remaining 50% apartment without window have hardwood floors.
40% of the apartment do not have hardwood floors i.e. 60 % have hardwood floor
Therefore percent of the apartments with windows have hardwood floors is
=83%
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When -29/8 is written as a decimal it becomes
Which is equivalent to -3.63, rounded to the nearest hundredth.
Now from here we will be able to tell if they're < , > or =
So, -3.63 is > -3.62
ANSWER: -29/8 > -3.62
Which is equivalent to -3.63, rounded to the nearest hundredth.
Now from here we will be able to tell if they're < , > or =
So, -3.63 is > -3.62
ANSWER: -29/8 > -3.62
Answer:
Step-by-step explanation:
1). 10 =
10(7 + x) = 1 + 7x
70 + 10x = 7x + 1
10x - 7x = 1 - 70
3x = -69
x = -23
2). 0.2 =
0.2(12 + x) = 6 + 2x
2.4 + 0.2x = 6 + 2x
2.4 - 6 = 2x - 0.2x
1.8x = -3.6
x = -2
3). 0.8 =
0.8(x + 0.5) = x
0.8x + 0.4 = x
x - 0.8x = 0.4
0.2x = 0.4
x = 2
4). 3.5 =
3.5(0.5 - x) = 4 + 2x
1.75 - 3.5x = 4 + 2x
-3.5x - 2x = 4 - 1.75
-5.5x = 2.25
x = -
x = -
Answer:
a)
b) 69.764
Step-by-step explanation:
1) 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".
2) Part a
Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability on this way:
And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.
3) Part b
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
Both conditions are equivalent on this case. We can use the z score again in order to find the value a.
As we can see on the figure attached the z value that satisfy the condition with 0.95 of the area on the left and 0.05 of the area on the right it's z=1.64. On this case P(Z<1.64)=0.95 and P(z>1.64)=0.05
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got
So the value of height that separates the bottom 95% of data from the top 5% is 69.764.
