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.
To get an average score of 80% (out of four exams), a total of 4*80%=320% is needed, so the minimum required for the 4th test is 320-(75+97+60)=88.
To get an average score of 89% (out of four exams), a total of 4*89%=356% is needed, so the maximum required for the 4th test is 356-(75+97+60)=124, which is impossible.
So the next exam grade must range between 88 and 100 to get a grade b in the class.
Hoped I help! Mark brainly it would help<3
Answer:
2:3
Step-by-step explanation:
<u>First convert years to months: 3 years = 36</u>
24:36
<u>Then simplify the ratio</u>
24:36
24/2:36/2
12/2:18/2
6/3:9/3
2:3
Answer: 2:3
Answer:
x>7
Step-by-step explanation:
Answer:
Step-by-step explanation:
In any "solve for" scenario, you identify what operations are performed on the variable of interest, then undo them in reverse order.
Here, the square root of d is multiplied by a constant. To undo these operations, we first divide by the constant. That gives ...
Then, we square both sides of the equation to undo the square root:
This matches choice C.
