Answer:
The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
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 is the reading speed of a sixth-grader whose reading speed is at the 90th percentile
This is the value of X when Z has a pvalue of 0.9. So it is X when Z = 1.28.




The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
Step-by-step explanation:
28. a=422000 (1+12%)^8
=1044856.46
29 a=13000 (1+15%)^-5
=6463.29
30 a=1250 (1+8%)^11
=2914.548
using compound interest formula
<h3>
Answer: B. Graph is nearly symmetrical</h3>
Explanation:
Given information:
- A number line going from 2 to 11.
- 0 dots are above 2.
- 0 dots are above 3.
- 1 dot is above 4.
- 2 dots are above 5.
- 4 dots are above 6.
- 4 dots are above 7.
- 3 dots are above 8.
- 2 dots are above 9.
- 2 dots are above 10.
- 0 dots are above 11.
From that we can see the data set is {4,5,5,6,6,6,6,7,7,7,7,8,8,8,9,9,10,10} which produces the dot plot you see in the image attachment below.
It's a bit tricky to see, but the graph is nearly symmetrical. If we were to remove the blue points in the dot plot I provided, then we'll get a perfectly symmetrical distribution. Symmetrical means one half is a mirror copy of the the other half. The center line of a symmetrical distribution is both the mean and median.
To find 2/3 of an hour first we will divide 1 hour that is 60 mins into 3parts so we will get 20 mins.