问题如下：
Find the p-value for the following t-test statistics of the null hypothesis, .
a. Statistic: 1.45, Alternative: Two-sided
b. Statistic: 1.45, Alternative: One-sided upper
c. Statistic: 1.45, Alternative: One-sided lower
d. Statistic: -2.3, Alternative: One-sided upper
e. Statistic: 2.7, Alternative: Two-sided
选项：
解释：
a. In a two-sided test, the p-value is the area under the normal curve for values greater than 1.45 or less than -1.45. This is twice the area less than -1.45, or 2 * 0.074. = .148.
b. In a one-sided upper test, we need the area above 1.45. This is half the previous answer, or 0.074.
c. In a one-sided lower test, we need the area under the curve for values less than 1.45. This is just 1 - 0.074 = .926.
d. Here we need to probability under the normal curve for values above -2.3, which is 1 minus the area less than -2.3, or 1 - 0.01 = 0.99.
e. Because it is a two-sided alternative, we need that area for values larger than 2.7 or less than -2.7, which is twice the area less than -2.7. This value is 2 * .0034 = .0068.
需要通过查表找到这些标准差倍数对应的累计概率，能不能讲下如何通过查表找到对应的累计概率的
