Answer:
The minimum score a person must have to qualify for the society is 162.05
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
Test scores are normally distributed with a mean of 140 and a standard deviation of 15. This means that
.
What is the minimum score a person must have to qualify for the society?
Since the person must score in the upper 7% of the population, this is the X when Z has a pvalue of 0.93.
This is
.
So




The minimum score a person must have to qualify for the society is 162.05
I'm going to assume that your function is f(x) = 1 + x^2 (NOT x2).
I suspect you're trying to estimate the "area under the curve of f(x) = 1 + x^2. You need to use this or a similar description to explain what you're doing.
Also, you need to specify whether you want "left end points" or "right end points" or "midpoints." Again I must assume you want one or the other (and will assume that you meant "left end points").
First, let's address the case n=3. You must graph f(x) = 1 + x^2 between -1 and +1. We will find the "lower sum," using "left end points." The 3 x-values are {-1, -1/3, 1/3}. Evaluate the function f(x) = 1 + x^2 at these 3 x-values. Keep in mind that the interval width is 2/3.
The function (y) values are {0, 2/3, 4/3}.
Sorry, Michael, but I must stop here and await clarification from you regarding what you've been told to do in this problem. Otherwise too much guessing (regarding what you meant) is necessary. Please review the original problem and ensure that you have copied it exactly as presented, and also please verify whether this problem does indeed involve estimating areas under curves between starting and ending x-values.
-6 is the answer to the problem.
Answer:
it is very simple -5 =(5)(-1)=(x+4)(2x-3).so compare( 5)=(x+4) and (x=1) it can be solved by mind.....(2x^2)+5x-7=0 then