Answer:
24.8 mins
Step-by-step explanation:
We'll begin by generating a table indicating the time mark (mid time) for the 50 people.
This is illustrated below
Time > timemark > frequency
0 – 10 > 10/2 = 5 > 5
10 – 20 > (10+20)/2 = 15 > 15
20 – 30 > (20+30)/2 = 25 > 13
30 – 40 > (30+40)/2 = 35 > 10
40 – 50 > (40+50)/2 = 45 > 7
The mean time for the 50 people is given by:
Mean = summation (mid time x frequency) / total frequency
Mean = [5x5 + 15x15 + 25x13 + 35x10 + 45x7] / 50
Mean = [25 + 225 + 325 + 350 + 315] / 50
Mean = 1240 / 50
Mean = 24.8 mins
Answer:
6
Step-by-step explanation:

Use long or synthetic division
The correct choice is B
Answer:
The probability that the student's IQ is at least 140 points is of 55.17%.
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:
University A: 
a) Select a student at random from university A. Find the probability that the student's IQ is at least 140 points.
This is 1 subtracted by the pvalue of Z when X = 140. So



has a pvalue of 0.4483.
1 - 0.4483 = 0.5517
The probability that the student's IQ is at least 140 points is of 55.17%.
Answer:
(a) 2% (b) 15
Step-by-step explanation:
(a):
80 - blue (32%)
60 - white (24%)
50 - red (20%)
45 - black (18%)
10 - silver (4%)
Total: 245
5 - other (2%)
(b):
60 - white
45 - black
Difference: 15