The manager went over the sales of mobile phones at the store and found that the mean sale was 45, with a standard deviation of 4. On a particular day, 52 mobile phones were sold.
What is the z-score of the sale of mo
...
The manager went over the sales of mobile phones at the store and found that the mean sale was 45, with a standard deviation of 4. On a particular day, 52 mobile phones were sold.
What is the z-score of the sale of mobile phones on that day?
-28
28
1.75
-1.75
RATIONALE
Recall that the z-score can be calculated with the following formula:
The given value is 52 phones, the mean is 45 phones, and the standard deviation is 4 phones. Plug these values in to get the following z-score:
This also tells us that 52 is 1.75 z-scores or standard deviations above the mean.
CONCEPT
Standard Scores and Z-Scores I need help with this question 2
In a poll of 300 preschoolers, 125 said they preferred chocolate ice cream, 71 said they preferred vanilla, 100 said they preferred cookies & cream, and 4 said they had never eaten ice cream.
If a pie chart were to be made showing the preference for each flavor, the central angle for the chocolate ice cream sector would be .
41°
5°
150°
124°
RATIONALE
Recall that to get the angle for something in a pie chart we use the following formula:
open parentheses fraction numerator v a l u e over denominator t o t a l space v a l u e end fraction close parentheses times 360 degree
So in this case, the central angle for the chocolate ice cream sector would be:
CONCEPT
Bar Graphs and Pie Charts
I need help with this question 3
The first quartile (Q1) value from the above box plot is .
47
40
65
54
RATIONALE
Note the value for Q1 is the left edge of the box, which is 47.
CONCEPT
Five Number Summary and Boxplots I need help with this question
4
Select the statement that accurately describes unimodal distribution.
A distribution in which two distinct values are more frequent than the other values.
A distribution in which the values are distributed uniformly.
A distribution in which one value is more frequent than other values.
A distribution in which numerous values are more frequent than other values.
RATIONALE
Recall the mode is the most frequently occurring value. If a distribution is unimodal, it simply means there is one value that occurs most frequently.
CONCEPT
Shapes of Distribution
I need help with this question 5
Choose the statement that correctly describes a normal distribution.
Approximately 68% of the values are greater than the mean value.
The approximate percent of values lying within three standard deviations of the mean is 49.85%.
Approximately 68% of the values lie within one standard deviation of the mean.
The approximate percent of values lying within two standard deviations of the mean is 47.5%.
RATIONALE
The normal distribution follows the empirical rule. This tells us that within one standard deviation of the mean, we should find roughly 68% of the data.
CONCEPT
Normal Distribution
I need help with this question 6
Sara wonders what percentage of her students answered at least half of the quiz questions incorrectly.
CONTINUED......................
[Show More]
