Complete question :
Standardized tests: In a particular year, the mean score on the ACT test was 19.3 and the standard deviation was 5.3. The mean score on the SAT mathematics test was 532 and the standard deviation was 128. The distributions of both scores were approximately bell-shaped. Round the answers to at least two decimal places. Part: 0/4 Part 1 of 4 (a) Find the z-score for an ACT score of 26. The Z-score for an ACT score of 26 is
Answer:
1.26
Step-by-step explanation:
Given that:
For ACT:
Mean score, m = 19.3
Standard deviation, s = 5.3
Zscore for ACT score of 26;
Using the Zscore formula :
(x - mean) / standard deviation
x = 26
Zscore :
(26 - 19.3) / 5.3
= 6.7 / 5.3
= 1.2641509
= 1.26
She can get $12. X= ($42)(2/7)
Answer:
17.5 or 35
Step-by-step explanation:
because 350/10=35
350/12=17.5
Answer:
And we can find this probability using excel or the normal standard tabe and we got:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the temperatures of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using excel or the normal standard tabe and we got: