The population standard deviation for the heights of dogs, in inches, in a city is 7.5 inches. If we want to be 90% confident that the sample mean is within 2 inches of the true population mean, what is the minimum sample size that can be taken

39

Step-by-step explanation:

Formula of sample size :

, where = critical z-value for confidence level , = population standard deviation , E = margin of error.

Hence, the minimum sample size that can be taken = 39

there are many solutions.

step-by-step explanation:

step 1: simplify both sides of the equation.

4x+6=4x^2+10x−4

step 2: subtract 4x^2+10x-4 from both sides.

4x+6−(4x^2+10x−4)=4x^2+10x−4−(4x^2+10x−4)

−4x^2−6x+10=0

step 3: factor left side of equation.

−2(2x+5)(x−1)=0

step 4: set factors equal to 0.

x=-5/2 or x=1