Answer:
25
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 = 175cm
Standard deviation = 6 cm
Percentage of students below 163 cm
163 = 175 - 2*6
So 163 is two standard deviations below the mean.
By the Empirical rule, 95% of the heights are within 2 standard deviations of the mean. The other 100-95 = 5% are more than 2 standard deviations of the mean. Since the normal distribution is symmetric, 2.5% of them are more than 2 standard deviations below the mean(so below 163cm) and 2.5% are more than two standard deviations above the mean.
2.5% of the students have heights less than 163cm.
Out of 1000
0.025*1000 = 25
25 is the answer
as you already know, the equation y=-7/4x-2, is already in slope-intercept form and thus its slope is the coefficient of the "x", namely -7/4.
parallel lines have the same exact slope, so a parallel line to this one will also have a slope of -7/4, and it passes through 4,2,

Answer:
(9a^2b^2(2ab - 3b + 4a).
Step-by-step explanation:
Take out the GCF.
The GCF is 9a^2b^2 so the factors are
(9a^2b^2(2ab - 3b + 4a).
Answer:
The margin of error is approximately 0.3
Step-by-step explanation:
The following information has been provided;
The sample size, n =225 students
The sample mean number of hours spent studying per week = 20.6
The standard deviation = 2.7
The question requires us to determine the margin of error that would be associated with a 90% confidence level. In constructing confidence intervals of the population mean, the margin of error is defined as;
The product of the associated z-score and the standard error of the sample mean. The standard error of the sample mean is calculated as;

where sigma is the standard deviation and n the sample size. The z-score associated with a 90% confidence level, from the given table, is 1.645.
The margin of error is thus;

Therefore, the margin of error is approximately 0.3
Answer:
The solution of this system is (10,14) and it means that there are 10 three point questions and 14 five point questions.
Step-by-step explanation:
In order to find the number of questions of each kind we need to solve the given system as shown below:

If we multiply the first equation by -3 and sum it with the second equation we can isolate the "y" variable and solve for its value:

We can use this value to find "x":

The solution of this system is (10,14) and it means that there are 10 three point questions and 14 five point questions.