Correct Ans:Option A. 0.0100
Solution:We are to find the probability that the class average for 10 selected classes is greater than 90. This involves the utilization of standard normal distribution.
First step will be to convert the given score into z score for given mean, standard deviation and sample size and then use that z score to find the said probability. So converting the value to z score:

So, 90 converted to z score for given data is 2.326. Now using the z-table we are to find the probability of z score to be greater than 2.326. The probability comes out to be 0.01.
Therefore, there is a 0.01 probability of the class average to be greater than 90 for the 10 classes.
Answer:
y = -1
Step-by-step explanation:
The standard form of equation of a line is y = mx+b
m is the slope
b is the y intercept
Get the coordinate of the point of interception of the line 2x - y = 9 and 3x - 7y = 19
Make y the subject of the formula in both expressions
For 2x - y = 9
- y = 9- 2x
y = 2x - 9
Similarly for 3x - 7y = 19
-7y = 19 - 3x
7y = 3x - 19
y = 3/7 x - 19/7
Equating both expressions
2x - 9 = 3/7 x - 19/7
Multiply through ny 7
14x - 63 = 3x - 19
14x - 3x = -19 + 63
11x = 44
x = 44/11
x = 4
Since y =2x - 9
y = 2(4) - 9
y = 8-9
y = -1
Hence the coordinate of intersection is at (4, -1)
Get the equation of the line passing through (-3, -1) and (4, -1)
Slope m = -1+1/4+3
m = 0/7
m = 0
Get the intercept
Substitute m = 0 and (-3, -1) into y = mx+b
-1 = 0(-3) + b
-1 = b
b = -1
Get the required equation
Recall that y = mx + b
y = 0x + (-1)
y = -1
Hence the required equation is y = -1
Answer:
Options (B) and (E)
Step-by-step explanation:
Area of ΔABC = 
= 
= 42 in²
Area of trapezoid ADEC =
[Here,
and
are the parallel sides and 'h' is the height of the isosceles trapezoid given]
= 
= 96 in²
Area of the pentagon = Area of triangle ABC + Area of trapezoid ADEC
= 42 + 96
= 138 in²
Therefore, Options (B) and (E) are the correct options.
Answer:
8.5x10^-5
Step-by-step explanation:
Move the decimal over between the 8 and the 5, it "hops" 5 times. Since it moved over right, make it negative
To solve an equation for one variable, we will utilize PEMDAS ( parentheses, exponents, multiplication/division, add/subtract) but backwards. So we will first add/subtract any numbers to the other side to get the variable by itself. We will then divide/multiply any numbers to get the variable by itself.