Suppose scores on exams in statistics are normally distributed with an unknown population mean. A sample of 26 scores is given below. Use Excel to find a 90% confidence interval for the true mean of statistics exam scores. Round your answers to one decimal place and use increasing order.

Step-by-step explanation:

Using the formula for calculating confidence interval

CI = xbar±z×S/√n

xbar is the mean of the sample

z is the z score at 90% = 1.645

S is the standard deviation of the score

n is the sample size = 26

Since we are not given the scores, we can assume the values of our mean and standard Deviation

Let xbar = 38

S = 3.0

Substitute the given values into the formula

CI = 38±(1.645×3.0/√26)

CI = 38±(1.645×3.0/5.099)

CI = 38±(1.645×0.5884)

CI = 38±0.9678

CI = (38-0.9678, 38+0.9678)

CI = (38.0322, 38.9678)

CI = (38.0, 38.9)

Hence the 90% confidence interval for the true mean of statistics exam scores is 38.0≤p≤38.9

Note that the we will need to generate the mean and standard deviation from the data but since we are not given the required data, we had to assume the value we used in calculation.

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

78.59 is the mean

step-by-step explanation: