X +(-5y)= 13
-x+ 9y =(-17)
0+<u>4y</u>=<u>-4</u>
4 4
y=1
x+-5(1)=13
x-5=13
+5 <u>+5
</u> x=18
y=1
Answer:
4
Step-by-step explanation:
i got it right on the test
Answer:
a.) Minimum test score = 41
Maximum test score = 95
b.)An approximate value of the standard deviation is 9.
Step-by-step explanation:
The given set of test scores is approximately bell shaped.
The mean of the test scores,
= 68
The range of the data set = 54.
a.) i.) Minimum test score = 
ii.) The maximum test score = 
b.) From the 68-95-99.7 rule, also known as the Empirical rule, tell us that an approximation of the range is 3 standard deviations either way from the mean. So from this rule we can say that the minimum can also be found from
and the maximum can also be approximated as
.
From the above we can say that the range can be written as

∴ 
∴ 
Therefore an approximate value of the standard deviation is 9.