C) x+3
first one factors to (x+3)(x-3)
second factors to (x+3)(x-2)
Answer:
Step-by-step explanation:
If 65% equals 147
Then to maintain 70% there is a need for 5% more
<u>Which equals</u>
Answer:
See below
Step-by-step explanation:
For a parallelogram m < A = m < C so:-
75 + 5x = 87 + 3x
2x = 12
x = 6
and m< A = 75 + 30 = 105
and m < C = 87 + 18 = 105
Now if the other 2 angles are = 75 degrees( that is the same side angles add up to 180 degrees) we have proved that it is a parallelogram.
m < B = m < D
111 - 6x = 39 + 6x
-12x = -72
x = 6
m < B = 111 - 36 = 75 and m < D = 39 + 36 = 75
So this has been proved.
Answer:
Let X the random variable of interest "Number of correct anwers on the tet", on this case we now that:
And the expected value is given by:
Step-by-step explanation:
Previous concepts
A Bernoulli trial is "a random experiment with exactly two possible outcomes, "success" and "failure", in which the probability of success is the same every time the experiment is conducted". And this experiment is a particular case of the binomial experiment.
The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".
The probability mass function for the Binomial distribution is given as:
Where (nCx) means combinatory and it's given by this formula:
Solution to the problem
Let X the random variable of interest "Number of correct anwers on the tet", on this case we now that:
And the expected value is given by:
Answer:
We can conclude the mean cost is larger for adopting children from Russia.
Step-by-step explanation:
To answer this question we can perform an hypothesis testing on the differences of the means with the following null and alternative hypothesis:
The significance level we assume is 0.05.
First we calculate the mean standard error:
The harmonic mean of the sample sizes is:
Then we can calculate the estimated standard deviation as:
The t-statistic can be calculated as:
The degrees of freedom are .
We can look up the P-value in a table or applet. For t=-4.015 and df=32, the P-value is 0.00017.
The P-value is smaller than the significance level, so the effect is significant and the null hyphotesis (China cost is equal or less than in Russia) is rejected.
We can conclude the mean cost is larger for adopting children from Russia.