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.
Answer:
H0 : μ1 = μ2
H0 : μ1 < μ2
Step-by-step explanation:
Given :
Early studiers, group 1, mean μ1
Late studiers, group 2 ; mean, μ2
To test the claim that students who study earlier have an average score that is less than the average score for students
The null hypothesis ; there is no difference in average score
H0 : μ1 = μ2
Alternative hypothesis is early studiers means is less than average score of late studiers
H0 : μ1 < μ2
Answer:
-3
Step-by-step explanation:
Three subtracted by a square of a number. So, let's say the number is x. The square of it is . So -3 is three subtracted by a square of a number.
Answer:
5.5 miles over 2 hours--> 5.5/2= 2.75 miles per hour was his average walking speed. 5.5 miles over 2.5 hours --> 5.5/2.5= 2.2 miles per hour on the return trip meaning that his average speed was (2.75-2.2= 0.55) 0.55 miles per hour lower on the return trip
Step-by-step explanation:
I hope this helps you :)
<em><u>-KeairaDickson</u></em>
