We are performing a one-sample z-test about mean. The sample size is 64, the sample mean 56.7, the sample standard deviation is 30, and the testing mean is 60. What is the value of the test statistic?

-0.880

Step-by-step explanation:

Mean X = 56.7

Sd = 30

N = sample size = 64

Null hypothesis:

H0:u = 60

Alternative hypothesis:

H1:u not equal to 60

This corresponds to a 2 tailed test. So we will have to use a z test with 1 mean, known population and standard deviation

Level of significance = 0.05

Z critical value = 1.96

The test statistic

Z = X - u/sd/√n

= 56.7 - 60/30√64

= -0.880

The test statistic is equal to -0.880

answer: standard form is ax^2 + bx + c = 0

step-by-step explanation:

standard form is ax^2 + bx + c = 0

(2x + 1)(x - 2) = 0

distribute to get into standard form

2x^2 - 4x + x - 2 = 0

2x^2 - 3x - 2 = 0

a = 2, b= -3, c = -2

a is your answer

30

step-by-step explanation:

times by times