Answer:
$1
Step-by-step explanation:
Let's call the ringtone r. If the ringtone and $3 equals $4, then we can write the equation $4=$3+r. To solve, all you have to do is isolate the r by subtracting 3 on each side.
N-1(-1/2) is the formula because the sequence is taking half of the previous number and changing its sign
Answer:
x = 30
Step-by-step explanation:
Since this is a right triangle,
90 = (x + 20) + (x + 10)
90 = x + x + 20 + 10
90 = 2x + 30
90 - 30 = 2x
60 = 2x
60/2 = 2x/2
30 = x
Check:
x + 20
30 + 20 = 50
x + 10
30 + 10 = 40
50 + 40 = 90
Hope this helps!
Answer: the answer is 11
Step-by-step explanation: to find the value of x, you must find the average of the two bases. So the equation would be 56= 4x+2x-10. Once you simplify that, you get x=11.
Answer:
47.06% of the population has an IQ between 85 and 105.
Step-by-step explanation:
Problems of normally distributed samples are 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:

What percent of the population has an IQ between 85 and 105?
This is the pvalue of Z when X = 105 subtracted by the pvalue of Z when X = 85. So
X = 105



has a pvalue of 0.6293.
X = 85



has a pvalue of 0.1587
So 0.6293 - 0.1587 = 0.4706 = 47.06% of the population has an IQ between 85 and 105.