The z-score of a person who scored 128 on the exam is equal to 2.9
<h3>What is a
z-score?</h3>
A z-score is also referred to as a z-value or standard score and it can be defined as a measure of the distance between a raw score and the mean, when standard deviation units are used.
Mathematically, the z-score of a given sample score in a normal distribution can be calculated by using this formula:
Where:
- x represents the sample score.
- u represents the mean score.
- σ represents the standard deviation.
Substituting the given parameters into the formula, we have;
Z-score, z = (128 - 70)/(20)
Z-score, z = 58/20
Z-score, z = 2.9
Read more on z-scores here: brainly.com/question/26714379
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Answer:
8 minutes
Step-by-step explanation:
minutes Abel completed the race = time finished - time started
7:18 - 7:10 = 8 minutes
5 is 10% out of 50, just do 100% of 50 which is 50 therefore 10% of 50=5!
Answer:
Step-by-step explanation:
GIVEN: An urn contains 
green and 
pink balls. Four balls are randomly drawn from the urn in succession, with replacement. That is, after each draw, the selected ball is returned to the urn.
TO FIND: What is the probability that all 4 balls drawn from the urn are pink.
SOLUTION:
Total balls in urn 
Total green balls 
Total pink balls 
probability of getting a pink ball 
As selected ball is returned to the urn, therefore drawing a ball is an independent event.
probability of getting all 
balls pink 
Hence the probability that all 4 balls drawn from the urn are pink is
