Question

The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took the customers in the sample to check out was 3.1 minutes with a standard deviation of 0.5 minutes. We want to test to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes.

The test statistic is __
a. 1.96
b. 1.64
c. 2.00
d. 0.056

Answer 1

The value of x that satisfies the equation 2x² - 7x - 5 = 0 can be found using the quadratic formula. Upon solving, the two values of x are approximately x1 = 2.61 and x2 = -0.61 when rounded to two decimal places.

Step-by-step explanation:

To find the value of x that satisfies the equation 2x² - 7x - 5 = 0, we can use the quadratic formula:

x = ∛(-b ± √(b² - 4ac)) / (2a)

Here, a = 2, b = -7, and c = -5. Plugging these values into the formula, we get:

x = (∛7 ± √(49 - 4(2)(-5))) / (4)

x = (∛7 ± √(49 + 40)) / (4)

x = (∛7 ± √89) / (4)

Now, using a calculator, we find the square root of 89 and follow through with the formula to get our two decimal point values for x.

After calculating, we get the two possible values of x to be approximately x1 = 2.61 and x2 = -0.61 when rounded to two decimal places.